Process to prepare levulinic acid

ABSTRACT

The invention describes processes to prepare levulinic acid, formic acid and/or hydroxymethyl furfural from various biomass materials.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/563,276, filed Nov. 23, 2011, U.S. Provisional Patent ApplicationNo. 61/576,818, filed Dec. 16, 2011, U.S. Provisional Patent ApplicationNo. 61/581,006, filed Dec. 28, 2011, and U.S. Provisional PatentApplication No. 61/722,766, filed Nov. 5, 2012, all entitled “PROCESS TOPREPARE LEVULINIC ACID”, the contents of which are incorporated hereinin their entirety for all purposes.

FIELD OF THE INVENTION

The invention relates generally to the preparation and purification oflevulinic acid.

BACKGROUND OF THE INVENTION

Levulinic acid can be used to make resins, plasticizers, specialtychemicals, herbicides and as a flavor substance. Levulinic acid isuseful as a solvent, and as a starting material in the preparation of avariety of industrial and pharmaceutical compounds such as diphenolicacid (useful as a component of protective and decorative finishes),calcium levulinate (a form of calcium for intravenous injection used forcalcium replenishment and for treating hypocalcemia. The use of thesodium salt of levulinic acid as a replacement for ethylene glycols asan antifreeze has also been proposed.

Esters of levulinic acid are known to be useful as plasticizers andsolvents, and have been suggested as fuel additives. Acid catalyzeddehydration of levulinic acid yields alpha-angelica lactone.

Levulinic acid has been synthesized by a variety of chemical methods.But levulinic acid has not attained much commercial significance due inpart to the high cost of the raw materials needed for synthesis. Anotherreason is the low yields of levulinic acid obtained from most syntheticmethods. Yet, another reason is the formation of a formic acid byproductduring synthesis and its separation from the levulinic acid. Therefore,the production of levulinic acid has had high associated equipmentcosts. Despite the inherent problems in the production of levulinicacid, however, the reactive nature of levulinic acid makes it an idealintermediate leading to the production of numerous useful derivatives.

Cellulose-based biomass, which is an inexpensive feedstock, can be usedas a raw material for making levulinic acid. The supply of sugars fromcellulose-containing plant biomass is immense and replenishable. Mostplants contain cellulose in their cell walls. For example, cottoncomprises 90% cellulose. Furthermore, it has been estimated that roughly75% of the approximate 24 million tons of biomass generated oncultivated lands and grasslands are waste. The cellulose derived fromplant biomass can be a suitable source of sugars to be used in theprocess of obtaining levulinic acid. Thus, the conversion of such wastematerial into a useful chemical, such as levulinic acid, is desirable.

BRIEF SUMMARY OF THE INVENTION

A major issue in producing levulinic acid is the separation of purelevulinic acid from the byproducts, especially from formic acid andchar. Current processes generally require high temperature reactionconditions, generally long digestion periods of biomass, specializedequipment to withstand hydrolysis conditions, and as a result, the yieldof the levulinic acid is quite low, generally in yields of 10 percent orless.

Therefore, a need exists for a new approach that overcomes one or moreof the current disadvantages noted above.

The present invention surprisingly provides novel approaches to moreefficiently prepare levulinic acid in commercial quantities with highyields and high purities. Additionally, the production ofhydroxymethylfurfural is also described, which is an importantintermediate to the product of levulinic acid.

In one aspect, the use of a water insoluble cosolvent in the processesimproves the yields of the hydroxymethylfurfural or levulinic acid andhelps to reduce undesired byproducts. In another aspect, the use of highconcentration of acid, e.g., about 20-50 weight percent based on thetotal weight of reaction components and low reaction temperature(approximately 50-100° C.) helps to improve yield of desired productswith reduction of undesired byproducts.

In one aspect, HMF can be prepared first followed by a second step toprepare the levulinic acid.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description. As will be apparent, the inventionis capable of modifications in various obvious aspects, all withoutdeparting from the spirit and scope of the present invention.Accordingly, the detailed descriptions are to be regarded asillustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a flow diagram of one embodiment for a process to prepareand/or purify levulinic acid.

FIG. 1 b is a flow diagram of another embodiment for a process toprepare and/or purify levulinic acid.

FIGS. 2 a through 2 e provide information regarding recovery oflevulinic acid from Char; soluble and insoluble fractions. It wassurprisingly found that extraction of the char provided levulinic acidalmost exclusively, helping to further improve the production oflevulinic acid.

FIG. 3 provides an aspen flowsheet diagram depicting various reactorconfigurations.

FIG. 4 depicts an industrial scale process to produce levulinic acid.

FIGS. 5 a through 5 c are pictures showing reactor components afterproduction of levulinic acid in accordance with the present invention.

FIGS. 5 d through 5 g are pictures showing reactor components afterproduction of levulinic acid in accordance with the prior art.

DETAILED DESCRIPTION

In the specification and in the claims, the terms “including” and“comprising” are open-ended terms and should be interpreted to mean“including, but not limited to . . . . ” These terms encompass the morerestrictive terms “consisting essentially of” and “consisting of.”

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural reference unless thecontext clearly dictates otherwise. As well, the terms “a” (or “an”),“one or more” and “at least one” can be used interchangeably herein. Itis also to be noted that the terms “comprising”, “including”,“characterized by” and “having” can be used interchangeably.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art to which this invention belongs. All publications and patentsspecifically mentioned herein are incorporated by reference in theirentirety for all purposes including describing and disclosing thechemicals, instruments, statistical analyses and methodologies which arereported in the publications which might be used in connection with theinvention. All references cited in this specification are to be taken asindicative of the level of skill in the art. Nothing herein is to beconstrued as an admission that the invention is not entitled to antedatesuch disclosure by virtue of prior invention.

The present invention provides various advantages in the preparation oflevulinic acid, hydroxymethyl furfural and/or formic acid. The followinglist of advantages is not meant to be limiting but highlights some ofthe discoveries contained herein.

First, a biomass material can be used as the initial feedstock toprepare the levulinic acid, hydroxymethyl furfural and/or formic acid.This ability provides great flexibility in obtaining a constant sourceof starting material and is not limiting.

Second, the biomass can be a refined material, such as fructose,glucose, sucrose, mixtures of those materials and the like. As such,there is a plentiful supply of materials that can be converted into theultimate product(s). For example, sugar beets or sugar cane can be usedas one source. Fructose-corn syrup is another readily availablematerial. Use of such materials thus helps to reduce the costs toprepare the desired products.

Third, it has been discovered that use of high concentrations ofacid(s), generally about 20 weight percent or more (based on the totalmass of the reaction medium) provides a cleaner reaction product withless char and unwanted byproducts. It has also been found that use ofhigh concentrations of acid(s), generally up to 75 weight percent ormore, (based on the total mass of the reaction medium) provides fasterreaction times than lower acid concentrations used with the samereaction conditions.

Fourth, it has also been discovered that with the use of higherconcentrations of acid, the reaction conditions can be conducted at muchlower temperatures than are currently utilized in the literature. Again,this lessens the amount of char and byproducts from the reaction(s) thattake place and increases the yield of the desired product(s).

Fifth, it has also been discovered that with the methods of the presentinvention, the char that is created is much easier to remove from thereactor. For example, FIGS. 5 a, 5 b and 5 c depict internal PARRreactor components after carrying out methods according to the presentinvention with no additional cleaning. As can be seen in thephotographs, there is little to no char accumulated on the reactorcomponents. In comparison, FIGS. 5 d through 5 g depict internal PARRreactor components after carrying out methods according to the prior artwith no additional cleaning. As can be seen, there is significant charbuild up on the reactor components requiring large cleanup efforts.

Sixth, it has been advantageously found to treat the biomass material(s)in an aqueous environment with a water immiscible solvent. Not to belimited by theory, it is believed that the partitioning of the startingmaterials from the product(s) between the aqueous and non-aqueous layersprovides for one or more of: increased yield, reduced charring and/orby-products, faster reaction times and reduced reaction temperatures.

Seventh, it has also been found that the advantages of the new processconditions, including continuous addition of the biomass over a periodof time during the reaction can be incorporated into existing processesto improve yield, reduce costs, improve efficiency and improve purity ofproduct(s).

Eighth, the processes described herein can be performed via CSTR orcontinuous batch process conditions.

In one embodiment, this process uses a high concentration of sulfuricacid, which has several distinct advantages. For one, the reactions canbe run at lower temperatures compared to low acid processes and stillhydrolyze the sugars in a reasonable time frame. It has been discoveredthat under these high acid, low-temperature reaction conditions (e.g.,80 C-110° C.), the char byproduct that is formed is in the form ofsuspended particles that are easier to remove from the reactor and thatcan be filtered from the liquid hydrolysate product stream. In contrast,with low acid conditions, high temperature is required to effectivelyhydrolyze the sugar in a reasonable time frame and those conditionsproduce a char byproduct that coats the reactor components in such amanner that it is difficult to remove, and for the most part does notstay suspended in the reaction mixture. This high-acid reactionstrategy, however, makes it difficult to isolate the organic acidproducts (levulinic acid and formic acid) from the inorganic acidreagent. When small amounts of sulfuric acid are used, as is typical inthe prior art, the strong inorganic acid can effectively be neutralizedto its salt form by careful addition of stoichiometric amounts of base.At the high acid contents used here, however, the quantity of saltproduced would be excessive. Likewise, the use of an ion exchange columnis impractical because the large quantity of inorganic acid wouldquickly fill the capacity of the column.

Solvent extraction techniques, where the organic acids are preferablyextracted into an organic solvent, are preferred. Even here, the highmineral acid content poses challenges. The organic solvent should beinsoluble in the aqueous phase, but in some cases, the sulfuric acid candrive compatibility of the organic solvent and the aqueous phase. Whenthis happens, a portion of the organic solvent becomes soluble in theconcentrated sulfuric acid aqueous phase and the risk of solvent loss toside reactions increases. Even if the organic solvent is stable in theaqueous sulfuric acid phase, the organic solvent must be recovered fromthe aqueous stream for recycling to the extraction unit for optimizedeconomics. High mineral acid concentration also carries with it thepotential for higher mineral acid concentrations in the organic phase.When this happens, there is the risk of solvent loss to side reactionswith the mineral acid, particularly in the case when the organic streamis heated to distill the organic solvent. Therefore, solvent extractionof the organic acid products should ideally have at least some of thefollowing characteristics:

little to no miscibility with water;

little to no miscibility with the mineral acid;

selectively partition the organic acids into the organic solvent phase;

have low partitioning of the mineral acid into the organic solventphase;

have low reactivity between the organic extraction solvent and themineral acid;

have low reactivity between the organic extraction solvent & the organicacid products;

have the ability to remove or reduce any mineral acid that partitionsinto the organic phase;

easy to remove from organic acid, such as by backwashing ordistillation;

allow the neutralization the organic acids.

In one embodiment, the partition coefficient of the extraction solventfor levulinic acid is at least 0.3, more specifically, at least 0.5,more specifically, at least 0.7, more specifically, at least 1.0, morespecifically at least 1.3, more specifically, at least 1.5 morespecifically, at least 1.7, and more specifically at least 2.0. In oneembodiment, the partition coefficient of the extraction solvent forformic acid is at least 0.3, more specifically, at least 0.5, morespecifically, at least 0.7, more specifically, at least 1.0, morespecifically at least 1.3, more specifically, at least 1.5 morespecifically, at least 1.7, and more specifically at least 2.0, morespecifically, at least 2.3, more specifically, at least 2.5, morespecifically, at least 3.0, more specifically, at least 3.5, morespecifically, at least 4.0, more specifically, at least 5.0 morespecifically, at least 6.0, more specifically, at least 7.0, morespecifically, at least 8.0, and more specifically, at least 9.0.

In one embodiment, to conduct a CSTR reaction with a given “residencetime” t (in this case, t=typically 30 min to 1 hour) the volume of thereactor is selected such that the typical “residence time” of thereactants is the designed target. The mass of material held in thereactor is designed to be the product of the mass flow rate into thereactor and the residence time. Longer residence time=larger quantity ofmaterial held in the reactor. Slower feed rate=smaller quantity ofmaterial held in the reactor. In operation, it is desirable for the feedto be a constant flow rate and composition; also the exit stream is aconstant flow rate and composition, and the sum of the flow rates of allexit streams equals the flow rate of the feeds (on a mass basis).

Typically, the reactor goes through a start-up phase until the reactorachieves “steady state” wherein the reactor contents, temperature, andpressure only varies within a controlled range. After steady state isachieved, the reactor is continuously operated as long as desired (days,weeks, months, years). During operation, the feed is steady, and theexit stream is steady. The reactor contents are steady. But the averageresidence time of the reactor contents is designed and held constant.The reactor content composition is equal to the composition of the exitstreams.

During the startup phase, many strategies can be used to reach steadystate as quickly as possible. For example, the reactor contents may bestarted as 100% water, or fed with the desired steady state compositionof the reactor contents. The composition of the feed streams can beallowed to vary, and the flow rate of the exit stream may be varied toachieve steady state (anywhere from zero to equal to the feed rate).

It has been observed that the production of HMF could potentially leadto large amounts of undesirable char build up. For example, a CSTRdesign which is inadvertently designed so as to run at conditions whichgive a high HMF yield, could be expected to yield high char anddiscouraging results.

It is thus, one technical advantage of one embodiment of the inventionto provide a continuous reaction system in such a way to minimize theHMF concentration.

It has been observed in a batch reaction wherein the HMF concentrationstarts out at zero, builds to a peak, and then declines again to verylow levels. In a simple batch reaction, such a profile is difficult toavoid. Likewise, a single, continuous, plug-flow reactor couldexperience a similar HMF concentration along the length of the tube. Theinventors have found that in one embodiment, a carefully designedreaction system (for example, an initial CSTR followed by a plug flowreactor) could avoid having a high HMF concentration and still achievehigh conversion.

The following paragraphs provide for various aspects of the presentinvention. In one embodiment, in a first paragraph (1), the presentinvention provides a process to prepare levulinic acid comprising thesteps:

a) heating an aqueous solution of a mineral acid to about 60° C. toabout 110° C. in a reactor; and

b) adding high fructose corn syrup, a mixture of at least two differentsugars, sucrose, an aqueous mixture comprising fructose, an aqueousmixture comprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof to the heated aqueous acid in thereactor over a period of time to form a reaction mixture includinglevulinic acid. In one embodiment, the high fructose corn syrup, amixture of at least two different sugars, sucrose, an aqueous mixturecomprising fructose, an aqueous mixture comprising fructose and glucose,an aqueous mixture comprising hydroxymethylfurfural, an aqueous solutionof fructose and hydroxymethylfurfural, an aqueous mixture of glucose, anaqueous mixture of maltose, an aqueous mixture of inulin, an aqueousmixture of polysaccharides, or mixtures thereof that are added to thereaction mixture over time comprises from about 0.1 to about 25, morespecifically, from about 1 to about 20 and even more specifically fromabout 4 to about 15 percent by weight of the final mass of the reactionmixture. It is understood that as the sugar streams are added to thereactor, the sugar will continuously react with the mineral acid to formlevulinic acid and other materials. Thus, the final reaction mixture maycontain less than the described ranges of sugars. In another embodiment,the steady state concentration of the high fructose corn syrup, amixture of at least two different sugars, sucrose, an aqueous mixturecomprising fructose, an aqueous mixture comprising fructose and glucose,an aqueous mixture comprising hydroxymethylfurfural, an aqueous solutionof fructose and hydroxymethylfurfural, an aqueous mixture of glucose, anaqueous mixture of maltose, an aqueous mixture of inulin, an aqueousmixture of polysaccharides, or mixtures thereof in the reaction mixtureis from about 0.1 to about 25, more specifically, from about 1 to about20 and even more specifically from about 4 to about 15 percent byweight.

2. The process of paragraph 1, wherein the mineral acid is sulfuric acid(H₂SOi₄), hydrochloric acid (HCl), hydrobromic acid (HBr) or hydroiodicacid (HI).

3. The process of paragraphs 1 or 2, wherein the mineral acid percentageby weight is from about 5 to about 80 percent of the reaction mixture.

4. The process of paragraphs 1 or 2, wherein the mineral acid percentageby weight is from about 20 to about 80 percent of the reaction mixture.

5. The process of paragraphs 1 or 2, wherein the mineral acid percentageby weight is from about 20 to about 50 percent of the reaction mixture.

6. The process of any of paragraphs 1 through 5, wherein the highfructose corn syrup is present between about 1 and about 99 weightpercent of fructose and from about 99 to about 1 weight percent glucosewith the remainder water, wherein the sugar content is between about 1and about 99% by weight.

7. The process of any of paragraphs 1 through 6, wherein the highfructose corn syrup is added over a period of from about 0.1 to about 40hours.

8. The process of either of paragraphs 1 through 5, wherein the mixtureof at least two different sugars is between about 1 and about 99 weightpercent of fructose and from about 99 to about 1 weight percent glucosewith the remainder water, wherein the sugar content is between about 20and about 90% by weight.

9. The process of any of paragraphs 1 through 5 or 7, wherein themixture of at least two different sugars is added over a period of fromabout 0.1 to about 40 hours.

10. The process of any of paragraphs 1 through 5, wherein the aqueousmixture of fructose and glucose is between about 1 and about 99 weightpercent of fructose and from about 99 to about 1 weight percent glucosewith the remainder water, wherein the sugar content is between about 30and about 85% by weight.

11. The process of any of paragraphs 1 through 5 or 10, wherein theaqueous mixture of fructose and glucose is added over a period of fromabout 0.1 to about 40 hours.

12. The process of either of paragraphs 1 through 5, wherein the aqueoussolution of fructose contains from about 1 to about 100 percent fructoseby weight.

13. The process of any of paragraphs 1 through 5 or 12, wherein theaqueous solution of fructose is added over a period of from about 0.1 toabout 40 hours.

14. The process of either of paragraphs 1 through 5, wherein the aqueoussolution of hydroxymethylfurfural contains from about 0.1 to about 100percent hydroxymethylfurfural by weight.

15. The process of any of paragraphs 1 through 5 or 14, wherein theaqueous solution of hydroxymethylfurfural is added over a period of fromabout 0.1 to about 40 hours.

16. The process of any of paragraphs 1 through 5, wherein the aqueousmixture of fructose and HMF contains from about 0.1 to about 99.9 partsfructose, from about 99.9 to about 0.1 parts hydroxymethylfurfural andfrom about 10 to about 99.8 parts water by weight.

17. The process of any of paragraphs 1 through 5 or 16, wherein theaqueous mixture of fructose and hydroxymethylfurfural is added over aperiod of from about 0.1 to about 40 hours.

18. The process of any of paragraphs 1 through 5, wherein the aqueousmixture of glucose contains from about 0.1 to about 99.9 parts glucoseand from about 0.1 to about 99.9 parts water by weight.

19. The process of any of paragraphs 1 through 5 or 18, wherein theaqueous mixture of glucose is added over a period of from about 0.1 toabout 40 hours.

20. The process of any of paragraphs 1 through 5, wherein the aqueousmixture of maltose contains from about 0.1 to about 99.9 parts maltoseand from about 0.1 to about 99.9 parts water by weight.

21. The process of any of paragraphs 1 through 5 or 20, wherein theaqueous mixture of maltose is added over a period of from about 0.1 toabout 40 hours.

22. The process of any of paragraphs 1 through 5, wherein the aqueousmixture of inulin contains from about 0.1 to about 99.9 parts inulin andfrom about 0.1 to about 99.9 parts water by weight.

23. The process of any of paragraphs 1 through 5 or 22, wherein theaqueous mixture of inulin is added over a period of from about 0.1 toabout 40 hours.

24. The process of any of paragraphs 1 through 5, wherein the aqueousmixture of polysaccharides contains from about 0.1 to about 99.9 partspolysaccharides and from about 0.1 to about 99.9 parts water by weight.

25. The process of any of paragraphs 1 through 5 or 24, wherein theaqueous mixture of polysaccharides is added over a period of from about0.1 to about 40 hours.

26. The process of any of paragraphs 1 through 25, wherein the aqueoussolution of mineral acid is stirred.

27. The process of any of paragraphs 1 through 26, wherein the mixtureis heated for an additional period of time from about 0.1 hour to about20 hours at a temperature range of from about 25° C. to about 110° C.

28. The process of any of paragraphs 1 through 27, wherein the mixtureis optionally cooled to ambient temperature.

29. The process of any of paragraph 1 through 28, further comprising thestep of heating the mixture to a temperature of from about 25° C. toabout 160° C. to reduce any residual glucose levels.

30. The process of either paragraphs 1 through 29, wherein the aqueousmixture comprises fructose and the levulinic acid is produced in greaterthan about 65% molar yield, optionally greater than about 75%,optionally greater than about 80%, optionally greater than 85%,optionally greater than 90%.

31. The process of either paragraphs 1 through 29, wherein the aqueousmixture comprises glucose and the levulinic acid is produced in greaterthan about 45% molar yield, optionally greater than about 50%,optionally greater than about 55%, optionally greater than 60%,optionally greater than 65%.

32. The process of any of paragraphs 1 through 31, wherein any remainingfructose is not detected by liquid chromatography.

33. The process of any of paragraphs 1 through 32, wherein any remaininghydroxymethylfurfural is present at less than 0.5 weight percent in thelevulinic acid product.

34. The process of any of paragraphs 1 through 33, wherein ratio of themass of levulinic acid to the mass of dry solids is greater than 1:1.

35. The process of any of paragraphs 1 through 34, wherein less than 5weight percent of dry char is produced relative to the entire weight ofthe mixture.

36. The process of any of paragraphs 1 through 35, further comprisingfiltering out solids from the mixture including levulinic acid toprovide a first filtrate. In one embodiment, the filter is a candlefilter, a Neutche filter, a basket centrifuge, membrane filters, or acartridge filter.

37. The process of paragraph 36, wherein filtering is carried out withfilter media having pore size less than 30 microns.

38. The process of paragraph 36, wherein filtering is carried out withfilter media having pore size less than 20 microns.

39. The process of any of paragraphs 1 through 38, further comprisingcombining the mixture comprising levulinic acid with an extractionsolvent to create an extraction phase and a raffinate phase.

40. The process of paragraph 39, wherein the extraction solvent has apartition coefficient for levulinic acid from water of at least 0.3,optionally at least 0.5, optionally at least 1.0, optionally at least1.5, and optionally at least 2.0.

41. The process of paragraph 39 wherein the extraction solvent has apartition coefficient for formic acid from water of at least 0.3,optionally at least 0.5, optionally at least 1.0, optionally at least1.5, optionally at least 2.0, optionally at least 5.0, optionally atleast 7.0 and optionally at least 9.0.

42. The process of any of paragraphs 39 through 41 wherein theextraction solvent is selected from the group consisting of methyliosamyl ketone, methyl isobutyl ketone, diisobutyl ketone, acetophenone,cyclohexanone, isophorone, neopentyl alcohol, isoamyl alcohol,n-hexanol, n-heptanol, 2-ethyl hexanol, n-octanol, 1-nonanol,1-undecanol, phenol, 4-methoxyphenol, guaiacol, 2-sec butyl phenol,nonyl phenol, methylene chloride, methyl isobutyl carbinol, anisol,ethylene glycol di-n-butyl ether, castor oil, m-cresol, p-cresol,o-cresol, cresol mixtures, 60/40 m-cresol/p-cresol, 75/25m-cresol/p-cresol, diethyl carbonate, methyl salicylate, 2,4-dimethylphenol and mixtures thereof.

43. The process of any of paragraphs 39 through 42, further comprisingrecycling the raffinate phase to the reactor.

44. The process of paragraph 43, further comprising heating theraffinate phase from 120-180 C. In one embodiment, the method furthercomprises removing any additional solids that are formed, preferably byfiltration.

45. The process of paragraph 44, further comprising cooling theraffinate phase to less than 110 C. In one embodiment, the methodfurther comprises removing any additional solids that are formed,preferably by filtration.

46. The process of paragraph 45, further comprising adding high fructosecorn syrup, a mixture of at least two different sugars, sucrose, anaqueous mixture comprising fructose, an aqueous mixture comprisingfructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof to the raffinate phase in thereactor over a period of time to form a mixture including levulinicacid.

47. The process of any of paragraphs 39 through 46, further comprisingseparating levulinic acid, formic acid, or both from the extractionsolvent.

48. The process of any of paragraphs 36 through 47, wherein the solidsare washed with water to provide a second filtrate and the first andsecond filtrates are combined to form a final filtrate. In otherembodiments the solids are washed with water to provide a secondfiltrate and the first and second filtrates are not combined.

49. The process of any of paragraphs 1 through 48, wherein the reactoris a batch reactor.

50. The process of any of paragraphs 1 through 48, wherein the reactoris one or more CSTRs.

51. A process to prepare levulinic acid comprising the steps:

a) heating an aqueous solution of a mineral acid to about 60° C. toabout 110° C.;

b) adding a first aqueous mixture comprising fructose and glucose to theheated aqueous mineral acid over a period of time to form a mixtureincluding levulinic acid;

c) optionally cooling the mixture to room temperature; and

d) heating the mixture, optionally in a sealed reactor, from about 25°C. to about 160° C. under pressure of 75 psi or below;

e) optionally cooling the heated mixture of step d) to room temperature;and

f) filtering the mixture to provide a first filtrate and solids. In oneembodiment, the aqueous mixture comprising fructose and glucose areadded to the reaction mixture over time comprise from about 0.1 to about25, more specifically, from about 1 to about 20 and even morespecifically from about 4 to about 15 percent by weight of the finalmass of the reaction mixture. It is understood that as the sugar streamsare added to the reactor, the sugar will continuously react with themineral acid to form levulinic acid and other materials. Thus, the finalreaction mixture may contain less than the described ranges of sugars.In another embodiment, the steady state concentration of the aqueousmixture comprising fructose and glucose in the reaction mixture is fromabout 0.1 to about 25, more specifically, from about 1 to about 20 andeven more specifically from about 4 to about 15 percent by weight.

52. The process of paragraph 51, wherein the mineral acid is acid issulfuric acid (H₂SO₄), hydrochloric acid (HCl), hydrobromic acid (HBr)or hydroiodic acid (HI).

53. The process of either paragraphs 51 or 52, wherein the mineral acidpercentage by weight is from about 5 to about 80 percent of the mixtureincluding levulinic acid.

54. The process of any of paragraphs 51 through 52, wherein the solidscan be washed more than once to provide additional filtrates to becombined with the first filtrate to form a final filtrate.

55. The process of any of paragraph 50 through 52, wherein the finalfiltrate is treated with a water immiscible solvent to form a waterimmiscible layer and a raffinate.

56. The process of paragraph 55, wherein the water immiscible layer isseparated from the aqueous layer and subjected to distillation.

57. The process of any of paragraphs 55 or 56, wherein the waterimmiscible solvent is selected from the group consisting of methyliosamyl ketone, methyl isobutyl ketone, diisobutyl ketone, acetophenone,cyclohexanone, isophorone, neopentyl alcohol, isoamyl alcohol,n-hexanol, n-heptanol, 2-ethyl hexanol, n-octanol, 1-nonanol,1-undecanol, phenol, 4-methoxyphenol, guaiacol, 2-sec butyl phenol,nonyl phenol, methylene chloride, methyl isobutyl carbinol, anisol,ethylene glycol di-n-butyl ether, castor oil, m-cresol, p-cresol,o-cresol, cresol mixtures, 60/40 m-cresol/p-cresol, 75/25m-cresol/p-cresol, diethyl carbonate, methyl salicylate, 2,4-dimethylphenol and mixtures thereof.

58. The process of either of paragraphs 56 or 57, wherein thedistillation is performed under vacuum to afford a levulinic acidproduct.

59. The process of any of paragraphs 55 through 58, further comprisingthe steps:

a) combining the raffinate, and optionally a mineral acid with water toform a mixture comprising from about 5 to about 80% mineral acid;

b) heating the mixture to about 80° C. to about 110° C.;

c) adding a second aqueous solution of aqueous mixture of fructose andglucose to the mixture over a period of from about 0.1 to about 40hours.

60. The process of paragraph 59, wherein any of paragraphs 51 through 59are repeated one or more times.

61. An industrial process to process to prepare levulinic acidcomprising the integrated steps of reaction, solids filtration,extraction, distillation, and recycling of any of paragraphs 1 through60.

62. The process of paragraph 51 further comprising the step of adding afilter aid to the reaction mixture prior to solids removal by filtrationor centrifugation.

63. The process of any of paragraphs 51 through 62, wherein the mixtureincluding levulinic acid is filtered through a 0.1 micron filter toabout a 30 micron filter.

64. The process of any of paragraphs 51 through 63, wherein the mixturecomprising levulinic acid is subjected to process conditions, whereinthe water, mineral acid, the water immiscible solvent and optionallylevulinic acid is recycled.

65. The process of any of paragraphs 51 through 63 are carried out in abatch reactor.

66. The process of any of paragraphs 51 through 63 are carried out in aCSTR.

67. A process to prepare levulinic acid comprising the steps:

a) heating an aqueous solution of a mineral acid to about 60° C. toabout 110° C.;

b) adding high fructose corn syrup, a mixture of at least two differentsugars, sucrose, an aqueous mixture comprising fructose, an aqueousmixture comprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof to the heated aqueous mineral acidover a period of time to form a reaction mixture in a reactor to form amixture including levulinic acid and solids;

c) filtering the solids from the mixture, optionally after cooling;

d) adding a water immiscible liquid to the mixture so that the mixtureforms first and second layers, wherein greater than 90% of the mineralacid is in the first layer and greater than 90% of the water immiscibleliquid is in the second layer;

e) recovering levulinic acid and optionally formic acid from the secondlayer; and

f) recycling the first layer back to the reactor. In one embodiment, thehigh fructose corn syrup, a mixture of at least two different sugars,sucrose, an aqueous mixture comprising fructose, an aqueous mixturecomprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof are added to the reaction mixtureover time comprise from about 0.1 to about 25, more specifically, fromabout 1 to about 20 and even more specifically from about 4 to about 15percent by weight of the final mass of the reaction mixture. It isunderstood that as the sugar streams are added to the reactor, the sugarwill continuously react with the mineral acid to form levulinic acid andother materials. Thus, the final reaction mixture may contain less thanthe described ranges of sugars. In another embodiment, the steady stateconcentration of the high fructose corn syrup, a mixture of at least twodifferent sugars, sucrose, an aqueous mixture comprising fructose, anaqueous mixture comprising fructose and glucose, an aqueous mixturecomprising hydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof in the reaction mixture is fromabout 0.1 to about 25, more specifically, from about 1 to about 20 andeven more specifically from about 4 to about 15 percent by weight

68. The process of paragraph 67, further comprising heating the firstlayer from about 120° C. to about 180° C. for a period of time.

69. The process of paragraph 68, further comprising cooling the firstlayer to below 100° C.

70. The process of any of paragraphs 67 through 69, wherein the mineralacid is selected from the group consisting of sulfuric acid,hydrochloric acid, hydrobromic acid, hydroiodide and combinationsthereof.

71. The process of paragraph 70, wherein the mineral acid is sulfuricacid.

72. The process of any of paragraphs 67 through 71, wherein the mineralacid percentage by weight is from about 5 to about 80 percent of thereaction mixture.

73. The process of paragraph 72, wherein the mineral acid percentage byweight is from about 20 to about 80 percent of the reaction mixture.

74. The process of paragraph 72, wherein the mineral acid percentage byweight is from about 20 to about 50 percent of the reaction mixture.

75. The process of paragraph 71, wherein the mineral acid percentage byweight is from about 40 to about 80 percent of the reaction mixture.

76. The process of any of paragraphs 67 through 75, wherein the firstlayer is heated for a period of time sufficient to convert greater than90% of any glucose into levulinic acid.

77. The process of any of paragraphs 67 through 76, wherein the waterimmiscible liquid is selected from the group consisting of methyliosamyl ketone, methyl isobutyl ketone, diisobutyl ketone, acetophenone,cyclohexanone, isophorone, neopentyl alcohol, isoamyl alcohol,n-hexanol, n-heptanol, 2-ethyl hexanol, n-octanol, 1-nonanol,1-undecanol, phenol, 4-methoxyphenol, guaiacol, 2-sec butyl phenol,nonyl phenol, methylene chloride, methyl isobutyl carbinol, anisol,ethylene glycol di-n-butyl ether, castor oil, m-cresol, p-cresol,o-cresol, cresol mixtures, 60/40 m-cresol/p-cresol, 75/25m-cresol/p-cresol, diethyl carbonate, methyl salicylate, 2,4-dimethylphenol and mixtures thereof.

78. The process of any of paragraphs 67 through 77, wherein the highfructose corn syrup, a mixture of at least two different sugars,sucrose, an aqueous mixture comprising fructose, an aqueous mixturecomprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures added over a period of from about 0.1 toabout 40 hours.

79. The process of any of paragraphs 67 through 78, wherein the mixtureis heated for an additional period of time from about 0.1 hour to about20 hours at a temperature range of from about 25° C. to about 110° C.

80. The process of either paragraphs 67 through 79, wherein the mixturecomprises fructose and the levulinic acid is produced in greater thanabout 65% molar yield, optionally greater than about 75%, optionallygreater than about 80%, optionally greater than 85%, optionally greaterthan 90%.

81. The process of either paragraphs 67 through 79, wherein the aqueousmixture comprises glucose and the levulinic acid is produced in greaterthan about 45% molar yield, optionally greater than about 50%,optionally greater than about 55%, optionally greater than 60%,optionally greater than 65%.

82. The process of any of paragraphs 67 through 81, wherein the mass oflevulinic acid to the mass of solids ratio is greater than 1:1.

83. The process of any of paragraphs 67 through 82, wherein less than 5weight percent of dry char is produced relative to the entire weight ofthe mixture.

84. The process of any of paragraphs 67 through 83, wherein the solidsthat are formed do not adhere to glass, Teflon or metal surfaces.

85. The process of paragraph 84, wherein the metal surface is ahastelloy metal surface, alloy 20 metal surface, alloy 2205 metalsurface, AL6XN metal surface or zirconium metal surface.

86. The process of any of paragraphs 67 through 85, wherein the reactoris batch reactor.

87. The process of any of paragraphs 67 through 85, wherein the reactoris a CSTR.

The following paragraphs also provide for various aspects of the presentinvention. In one embodiment, in a first paragraph (1), the presentinvention provides a process to prepare levulinic acid or5-(hydroxylmethyl)furfural, comprising the steps:

mixing biomass with an aqueous portion, a water immiscible portion, andan acid to form a mixture; and

heating the mixture to a temperature of from about 50° C. to about 280°C. to provide levulinic acid or 5-(hydroxymethyl)furfural in the waterimmiscible portion.

1a. The process of paragraph 1, wherein the mixture is heated from about80° C. to about 250° C.

1b. The process of paragraph 1, wherein the mixture is heated from about100° C. to about 220° C.

1c. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 100° C.

1d. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 90° C.

1e. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 80° C.

1f. The process of paragraph 1, wherein the mixture is heated from about60° C. to about 80° C.

2. The process of paragraph 1, wherein the mixture is heated to refluxconditions.

3. The process of any of paragraphs 1 through 2, wherein the mixture isheated under pressure, wherein the pressure range is from about 10 psito about 1000 psi.

3a. The process of paragraph 3, wherein the pressure range of from about30 to about 500 psi.

3b. The process of paragraph 3, wherein the pressure range if from about50 to about 200 psi.

4. The process of any of paragraphs 1 through 3b, further comprising thestep of mixing the mixture.

5. The process of any of paragraphs 1 through 4, further comprising thestep of cooling the mixture after the mixture is heated.

6. The process of any of paragraphs 1 through 5, further comprising thestep of separating the water immiscible portion containing the levulinicacid or the 5-(hydroxymethyl)furfural from the aqueous portion.

7. The process of paragraph 6, further comprising the step of removingthe water immiscible portion from the levulinic acid or5-(hydroxymethyl)furfural.

8. The process of paragraph 7, wherein the water immiscible portion isremoved by distillation to provide a reaction material containing thelevulinic acid or 5-(hydroxymethyl)furfural.

9. The process of paragraph 8, further comprising the step of treatingthe reaction material with a solid sorbent.

9a. The process of paragraph 9, wherein the solid sorbent is/are piecesof wood, an ion exchange resin, optionally with a solvent, molecularsieves, optionally with a solvent, or activated carbon, optionally witha solvent.

10. The process of either paragraph 9 or 9a, further comprising thesteps of removing the levulinic acid or 5-(hydroxymethyl)furfural fromthe solid sorbent by heat, pressure, or by rinsing with water, aqueousbase or a polar solvent.

11. The process of any of paragraphs 1 through 10, wherein the biomasscomprises sludges from paper manufacturing process; agriculturalresidues; bagasse pity; bagasse; molasses; aqueous oak wood extracts;rice hull; oats residues; wood sugar slops; fir sawdust; naphtha;corncob furfural residue; cotton balls; raw wood flour; rice; straw;soybean skin; soybean oil residue; corn husks; cotton stems; cottonseedhulls; starch; potatoes; sweet potatoes; lactose; sunflower seed husks;sugar; corn syrup; hemp; waste paper; wastepaper fibers; sawdust; wood;residue from agriculture or forestry; organic components of municipaland industrial wastes; waste plant materials from hard wood or beechbark; fiberboard industry waste water; post-fermentation liquor;furfural still residues; and combinations thereof, a C5 sugar, a C6sugar, a lignocelluloses, cellulose, starch, a polysaccharide, adisaccharide, a monosaccharide or mixtures thereof.

12. The process of any of paragraph 11, wherein the biomass is fructose,sucrose, glucose or a mixture thereof.

13. The process of any of paragraphs 1 through 12, wherein the acid is amineral acid.

14. The process of paragraph 13, wherein the mineral acid is sulfuricacid, phosphoric acid, hydrochloric acid or mixtures thereof.

15. The process of either paragraph 13 or 14, wherein the concentrationof mineral acid is from about 1 percent to about 75 percent by weight ofthe mixture.

16. The process of paragraph 15, wherein the concentration of themineral acid is from about 5 percent to about 60 percent by weight ofthe mixture, more particularly from about 20 weight percent to about 50weight percent.

17. The process of any of paragraphs 1 through 12, wherein the acid isan organic sulfonic acid.

18. The process of paragraph 17, wherein the organic acid ispara-toluene sulfonic acid, naphthalene sulfonic acid, camphor sulfonicacid or n-dodecylbenzene sulfonic acid.

19. The process of any of paragraphs 1 through 18, further comprisingadding a phase transfer catalyst to the mixture.

20. The process of paragraph 19, wherein the phase transfer catalyst isan ammonium salt, a heterocyclic ammonium salt or a phosphonium salt.

21. The process of any of paragraphs 1 through 20, wherein the waterimmiscible portion is methyl isobutyl ketone, ethyl levulinate, butyllevulinate, cyclohexanone, toluene, methyl-THF, methyl-tertiary butylether, methyl isoamyl ketone, hexane, cyclohexane, chloro-benzene,methylene chloride, dichloroethane, ortho-dichlorobenzene, diisobutylketone, 2,6-dimethyl cyclohexanone, tetrahydrofuran or mixtures thereof.

22. The process of any of paragraphs 1 through 21, wherein the processis conducted in a continuously-stirred tank reactor (CSTR) or aplug-flow reactor (PFR).

23. The process of paragraph 22, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to biomass is added tothe reactor over a period of 1 hour and an equivalent weight amount isremoved during the same time period.

24. The process of paragraph 23, wherein the biomass is fructose.

25. The process of either paragraphs 23 or 24, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of 1 hour and an equivalent weight amount is removed during thesame time period.

26. The process of paragraph 22, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to biomass is added tothe reactor over a period of time t and an equivalent weight amount isremoved during the same time period t.

27. The process of paragraph 26, wherein the biomass is fructose.

28. The process of either paragraphs 26 or 27, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor overthe period of time t and an equivalent weight amount is removed duringthe same time period.

The process of any of paragraphs 1 through 21, wherein the process isconducted in a continuous addition batch reactor.

30. The process of paragraph 29, wherein the continuous addition batchprocess is conducted wherein a ratio of about 2:1 to about 5:1 water tobiomass is added to the reactor over a period of 1 hour.

31. The process of paragraph 30, wherein the biomass is fructose.

32. The process of either paragraphs 30 or 31, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of 1 hour.

33. The process of paragraph 29, wherein the continuous addition batchprocess is conducted wherein a ratio of about 2:1 to about 5:1 water tobiomass is added to the reactor over a period of time t.

34. The process of paragraph 33, wherein the biomass is fructose.

35. The process of either paragraphs 33 or 34, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor overthe period of time t.

The following paragraphs provide for additional aspects of the presentinvention. In one embodiment, in a first paragraph (1), the presentinvention provides a process to prepare levulinic acid or formic acid,comprising the steps:

mixing up to 50 weight percent of a fructose containing materialcomprising fructan, fructooligosaccharide, inulin, fructose,fructose-glucose blended corn syrup, sucrose or mixtures thereof, up to75 weight percent of an acid catalyst and at least 20 weight percentwater to equal 100 weight percent to form a mixture; and

heating the mixture to a temperature of from about 50° C. to about 280°C. to provide levulinic acid or formic acid.

1a. The process of paragraph 1, wherein the mixture is heated from about80° C. to about 250° C.

1b. The process of paragraph 1, wherein the mixture is heated from about100° C. to about 220° C.

1c. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 100° C.

1d. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 90° C.

1e. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 80° C.

1f. The process of paragraph 1, wherein the mixture is heated from about60° C. to about 80° C.

2. The process of any of paragraphs 1 through 1f, wherein the mixture isheated under pressure, wherein the pressure range is from about 10 psito about 1000 psi.

2a. The process of paragraph 2, wherein the pressure range of from about30 to about 500 psi.

2b. The process of paragraph 2, wherein the pressure range if from about50 to about 200 psi.

3. The process of any of paragraphs 1 through 2b, wherein the acid ispresent from about 10 weight percent to about 40 weight percent.

3a. The process of any of paragraphs 1 through 3, wherein the acid ispresent from about 20 weight percent to about 30 weight percent.

4. The process of any of paragraphs 1 through 3a, wherein the mixture isheated for 60 minutes or less.

5. The process of paragraph 4, wherein the mixture is heated for 30minutes or less.

6. The process of any of paragraphs 1 through 5, further comprising thestep of mixing the mixture.

7. The process of any of paragraphs 1 through 6, further comprising thestep of cooling the mixture after the mixture is heated.

8. The process of any of paragraphs 1 through 7, further comprising thestep of isolating the levulinic acid or the formic acid from solid huminby-product.

9. The process of paragraph 8, further comprising the step of treatingthe humin by-product with a solvent to provide a filtrate.

10. The process of paragraph 9, wherein the solvent is water,methylisobutyl ketone, methyl-THF, cyclohexanone, acetonitrile, acetone,methanol, ethanol, butanol, MTBE or mixtures thereof.

11. The process of either paragraph 9 or 10, wherein the isolatedlevulinic acid or formic acid and the filtrate are combined to provide afinal filtrate.

12. The process of paragraph 11, wherein the molar yield of levulinicacid is from about 50% to about 90%.

13. The process of paragraph 11, wherein the molar yield of formic acidis from about 50% to about 90%.

14. The process of any of paragraphs 1 through 13, further comprisingthe step of treating the mixture with a solid sorbent.

14a. The process of paragraph 14, wherein the solid sorbent is/arepieces of wood, an ion exchange resin, optionally with a solvent,molecular sieves, optionally with a solvent, or activated carbon,optionally with a solvent.

15. The process of either paragraph 14 or 14a, further comprising thesteps of removing the levulinic acid or 5-(hydroxymethyl)furfural fromthe solid sorbent by heat, pressure, or by rinsing with water, aqueousbase or a polar solvent.

16. The process of any of paragraphs 1 through 15, wherein the acid is amineral acid.

17. The process of paragraph 16, wherein the mineral acid is sulfuricacid, phosphoric acid, hydrochloric acid or mixtures thereof.

18. The process of any of paragraphs 1 through 17, wherein the processis conducted in a continuously-stirred tank reactor (CSTR) or aplug-flow reactor (PFR).

19. The process of paragraph 18, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to fructose or sugar isadded to the reactor over a period of 1 hour and an equivalent weightamount is removed during the same time period.

20. The process of paragraph 19, wherein a ratio of about 10:1 to about15:1 water to mineral acid is added to the reactor over a period of 1hour and an equivalent weight amount is removed during the same timeperiod.

21. The process of paragraph 18, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to fructose or sugar isadded to the reactor over a period of time t and an equivalent weightamount is removed during the same time period.

22. The process of paragraph 21, wherein a ratio of about 10:1 to about15:1 water to mineral acid is added to the reactor over the period oftime t and an equivalent weight amount is removed during the same timeperiod.

The following paragraphs provide for additional aspects of the presentinvention. In one embodiment, in a first paragraph (1), the presentinvention provides a process to prepare levulinic acid or formic acid,comprising the steps:

mixing a biomass material with an acid catalyst or supercritical waterto form a first mixture, wherein the biomass is converted to provideglucose;

treating the glucose with an isomerization catalyst or a base catalystto form a second mixture, wherein the glucose is converted intofructose;

mixing the fructose containing mixture with an acid and water form athird mixture; and

heating the third mixture to a temperature of from about 50° C. to about280° C. to provide levulinic acid or formic acid.

1a. The process of paragraph 1, wherein the biomass comprises sludgesfrom paper manufacturing process; agricultural residues; bagasse pity;bagasse; molasses; aqueous oak wood extracts; rice hull; oats residues;wood sugar slops; fir sawdust; naphtha; corncob furfural residue; cottonballs; raw wood flour; rice; straw; soybean skin; soybean oil residue;corn husks; cotton stems; cottonseed hulls; starch; potatoes; sweetpotatoes; lactose; sunflower seed husks; sugar; corn syrup; hemp; wastepaper; wastepaper fibers; sawdust; wood; residue from agriculture orforestry; organic components of municipal and industrial wastes; wasteplant materials from hard wood or beech bark; fiberboard industry wastewater; post-fermentation liquor; furfural still residues; andcombinations thereof, a C5 sugar, a C6 sugar, a lignocelluloses,cellulose, starch, a polysaccharide, a disaccharide, a monosaccharide ormixtures thereof.

1b. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 80° C. to about 250° C.

1c. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 100° C. to about 220° C.

1d. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 100° C.

1e. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 90° C.

1f. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 80° C.

1g. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 60° C. to about 80° C.

2. The process of any of paragraphs 1 through 1g, wherein the mixture isheated under pressure, wherein the pressure range is from about 10 psito about 1000 psi.

2a. The process of paragraph 2, wherein the pressure range of from about30 to about 500 psi.

2b. The process of paragraph 2, wherein the pressure range if from about50 to about 200 psi.

3. The process of any of paragraphs 1 through 2b, wherein the biomassconverting catalyst is hydrochloric acid, sulfuric acid, triflic acid,trifluoroacetic acid or mixtures thereof.

4. The process of any of paragraphs 1 through 3, wherein the glucoseisomerization catalyst is glucoisomerase.

5. The process of any of paragraphs 1 through 4, wherein the glucoseconverting base catalyst is a basic alkali or alkaline earth metalhydroxide or carbonate.

6. The process of any of paragraphs 1 through 5, wherein the thirdmixture contains about 0.1 to about 30 weight percent of a fructosecontaining material.

7. The process of paragraph 6, wherein the fructose containing materialcomprises fructan, fructooligosaccharide, inulin, fructose, fructosecorn syrup or mixtures thereof.

8. The process of paragraph 7, wherein the fructose containing materialis present from about 1 to about 99 weight percent.

9. The process of paragraph 1, wherein the third mixture contains up to50 weight percent of the acid.

10. The process of paragraph 9, wherein the acid is present from about 2to about 40 weight percent.

11. The process of paragraph 10, wherein the acid is a mineral acid.

12. The process of paragraph 11, wherein the mineral acid is sulfuricacid, phosphoric acid, hydrochloric acid or mixtures thereof.

13. The process of any of paragraphs 1 through 12, wherein the thirdmixture is heated for 60 minutes or less.

14. The process of paragraph 13, wherein the mixture is heated for 30minutes or less.

15. The process of any of paragraphs 1 through 14, further comprisingthe step of mixing one or more of the mixtures.

16. The process of any of paragraphs 1 through 15, further comprisingthe step of cooling the third mixture after the mixture is heated.

17. The process of any of paragraphs 1 through 16, further comprisingthe step of isolating the levulinic acid or the formic acid from solidhumin by-product.

18. The process of paragraph 17, further comprising the step of treatingthe humin by-product with a solvent to provide a filtrate.

19. The process of paragraph 18, wherein the solvent is water,methylisobutyl ketone, methyl-THF, cyclohexanone, acetonitrile, acetone,methanol, ethanol, butanol, MTBE or mixtures thereof.

20. The process of either paragraph 18 or 19, wherein the isolatedlevulinic acid or formic acid and the filtrate are combined to provide afinal filtrate.

21. The process of paragraph 20, wherein the molar yield of levulinicacid is from about 50% to about 90%.

22. The process of paragraph 20, wherein the molar yield of formic acidis from about 50% to about 90%.

23. The process of any of paragraphs 1 through 22, wherein the processis conducted in a continuously-stirred tank reactor (CSTR) or aplug-flow reactor (PFR).

24. The process of paragraph 23, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to biomass is added tothe reactor over a period of 1 hour and an equivalent weight amount isremoved during the same time period.

25. The process of paragraph 24, wherein the biomass comprises fructose.

26. The process of either paragraphs 24 or 25, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of 1 hour and an equivalent weight amount is removed during thesame time period.

27. The process of paragraph 23, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to biomass is added tothe reactor over a period of time t and an equivalent weight amount isremoved during the same time period.

28. The process of paragraph 27, wherein the biomass comprises fructose.

29. The process of either paragraphs 26 or 27, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of time t and an equivalent weight amount is removed during thesame time period.

30. The process of any of paragraphs 1 through 29, further comprisingthe step of treating the final filtrate with a solid sorbent.

31. The process of paragraph 30, wherein the solid sorbent is/are piecesof wood, an ion exchange resin, optionally with a solvent, molecularsieves, optionally with a solvent, or activated carbon, optionally witha solvent.

32. The process of either paragraph 30 or 31, further comprising thesteps of removing the levulinic acid or formic acid from the solidsorbent by heat, pressure, or by rinsing with water, aqueous base or apolar solvent.

The following paragraphs provide for additional aspects of the presentinvention. In one embodiment, in a first paragraph (1), the presentinvention provides a continuous process for producing levulinic acidfrom a biomass using a first reactor having an entrance and an exit anda second reactor having an entrance and an exit said process comprising,

continuously supplying a sample containing said biomass to said firstreactor through said entrance to said first reactor,

hydrolyzing said biomass in said first reactor at between 210° C. and230° C. for between 10 seconds and 100 seconds in the presence of awater immiscible liquid and mineral acid comprising between 1% and 5% byweight of said sample to produce hydroxymethylfurfural and otherreaction intermediates,

continuously removing an intermediate sample containing saidhydroxymethylfurfural and other reaction intermediates from said firstreactor through said exit of said first reactor in such a manner thatsubstantially no axial mixing occurs in said first reactor,

continuously supplying the intermediate sample that has been removedfrom said first reactor to said second reactor through said entrance tosaid second reactor,

hydrolyzing said hydroxymethylfurfural and other reaction intermediatesin said intermediate sample in said second reactor at between 195° C.and 215° C. for between 15 minutes and 30 minutes in the presence of,optionally a water immiscible liquid, and a mineral acid comprisingbetween 3% and 7.5% by weight of said intermediate sample to producelevulinic acid, and

continuously removing levulinic acid from said second reactor throughsaid exit of said second reactor, wherein the yield of levulinic acidremoved from said second reactor comprises at least 60% of thetheoretical yield.

2. The process of paragraph 1, wherein the biomass comprises sludgesfrom paper manufacturing process; agricultural residues; bagasse pity;bagasse; molasses; aqueous oak wood extracts; rice hull; oats residues;wood sugar slops; fir sawdust; naphtha; corncob furfural residue; cottonballs; raw wood flour; rice; straw; soybean skin; soybean oil residue;corn husks; cotton stems; cottonseed hulls; starch; potatoes; sweetpotatoes; lactose; sunflower seed husks; sugar; corn syrup; hemp; wastepaper; wastepaper fibers; sawdust; wood; residue from agriculture orforestry; organic components of municipal and industrial wastes; wasteplant materials from hard wood or beech bark; fiberboard industry wastewater; post-fermentation liquor; furfural still residues; andcombinations thereof, a C5 sugar, a C6 sugar, a lignocelluloses,cellulose, starch, a polysaccharide, a disaccharide, a monosaccharide ormixtures thereof.

3. The process of any of paragraphs 1 through 20, wherein the waterimmiscible liquid is methyl isobutyl ketone, ethyl levulinate, butyllevulinate, cyclohexanone, toluene, methyl-THF, methyl-tertiary butylether, methyl isoamyl ketone, hexane, cyclohexane, chloro-benzene,methylene chloride, dichloroethane, ortho-dichlorobenzene, diisobutylketone, 2,6-dimethyl cyclohexanone, tetrahydrofuran or mixtures thereof.

4. The process of any of paragraphs 1 through 3, further comprising thestep of treating the hydroxymethylfurfural from the first reactor or thelevulinic acid from the second reactor with a solid sorbent.

5. The process of paragraph 4, wherein the solid sorbent is/are piecesof wood, an ion exchange resin, optionally with a solvent, molecularsieves, optionally with a solvent, or activated carbon, optionally witha solvent.

6. The process of either paragraph 4 or 5, further comprising the stepsof removing the levulinic acid or formic acid from the solid sorbent byheat, pressure, or by rinsing with water, aqueous base or a polarsolvent.

The following paragraphs provide for still an additional aspect of thepresent invention. In one embodiment, in a first paragraph (1), thepresent invention provides a process for producing formic acid from acarbohydrate-containing material, the process comprising: introducing acarbohydrate-containing material to a first reactor; hydrolyzing thecarbohydrate-containing material in the first reactor in the presence ofa water immiscible liquid and a mineral acid for a first time period ata first temperature and a first pressure effective to form anintermediate hydrolysate comprising one or more sugars; transferring theintermediate hydrolysate from the first reactor to a second reactor;hydrolyzing the intermediate hydrolysate in the second reactor for asecond time period at a second temperature less than 195 degrees C. anda second pressure effective to form a hydrolysate product comprisingformic acid; and isolating the formic acid in a vapor from thehydrolysate product.

The following paragraphs provide for still additional aspects of thepresent invention. In one embodiment, in a first paragraph (1), thepresent invention provides a process to prepare levulinic acid or formicacid, comprising the steps:

mixing a biomass material with an acid catalyst or supercritical waterto form a first mixture, wherein the biomass is converted to provideglucose;

treating the glucose with an isomerization catalyst or a base catalystto form a second mixture, wherein the glucose is converted intofructose;

mixing the fructose containing mixture with an acid and water form athird mixture;

heating the third mixture at a temperature of from about 50° C. to about280° C.;

cooling the third mixture; and

treating the third mixture with an water immiscible solvent to form anaqueous layer and a water immiscible layer, providing levulinic acid orformic acid in the water immiscible layer.

1a. The process of paragraph 1, wherein the biomass comprises sludgesfrom paper manufacturing process; agricultural residues; bagasse pity;bagasse; molasses; aqueous oak wood extracts; rice hull; oats residues;wood sugar slops; fir sawdust; naphtha; corncob furfural residue; cottonballs; raw wood flour; rice; straw; soybean skin; soybean oil residue;corn husks; cotton stems; cottonseed hulls; starch; potatoes; sweetpotatoes; lactose; sunflower seed husks; sugar; corn syrup; hemp; wastepaper; wastepaper fibers; sawdust; wood; residue from agriculture orforestry; organic components of municipal and industrial wastes; wasteplant materials from hard wood or beech bark; fiberboard industry wastewater; post-fermentation liquor; furfural still residues; andcombinations thereof, a C5 sugar, a C6 sugar, a lignocelluloses,cellulose, starch, a polysaccharide, a disaccharide, a monosaccharide ormixtures thereof.

1b. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 80° C. to about 250° C.

1c. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 100° C. to about 220° C.

1d. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 100° C.

1e. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 90° C.

1f. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 80° C.

1g. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 60° C. to about 80° C.

2. The process of any of paragraphs 1 through 1g, wherein the mixture isheated under pressure, wherein the pressure range is from about 10 psito about 1000 psi.

2a. The process of paragraph 2, wherein the pressure range of from about30 to about 500 psi.

2b. The process of paragraph 2, wherein the pressure range if from about50 to about 200 psi.

3. The process of any of paragraphs 1 through 2b, wherein the biomassconverting catalyst is hydrochloric acid, sulfuric acid, triflic acid,trifluoroacetic acid or mixtures thereof.

4. The process of paragraph 1, wherein glucose converting isomerizationcatalyst is glucoisomerase.

5. The process of paragraph 1, wherein the glucose converting catalystis a basic alkali or alkaline earth metal hydroxide or carbonate.

6. The process of paragraph 1, wherein the third mixture contains about0.1 weight percent to about 30 weight percent of a fructose containingmaterial.

7. The process of paragraph 6, wherein the fructose containing materialcomprises fructan, fructooligosaccharide, inulin, fructose, fructosecorn syrup or mixtures thereof.

8. The process of paragraph 7, wherein the fructose containing materialis present from about 1 to about 99 weight percent.

9. The process of paragraph 1, wherein the third mixture contains up to50 weight percent of the acid.

10. The process of paragraph 9, wherein the acid is present from about 2to about 40 weight percent.

11. The process of paragraph 10, wherein the acid is a mineral acid.

12. The process of paragraph 11, wherein the mineral acid is sulfuricacid, phosphoric acid, hydrochloric acid or mixtures thereof.

13. The process of any of paragraphs 1 through 12, wherein the thirdmixture is heated for 60 minutes or less.

14. The process of paragraph 13, wherein the mixture is heated for 30minutes or less.

15. The process of any of paragraphs 1 through 14, further comprisingthe step of mixing one or more of the mixtures.

16. The process of any of paragraphs 1 through 15, further comprisingthe step of isolating the levulinic acid or the formic acid from solidhumin by-product.

17. The process of paragraph 16, wherein the isolation step isfiltration.

18. The process of paragraph 17, further comprising the step of treatingthe humin by-product with a solvent to provide a filtrate.

19. The process of paragraph 18, wherein the solvent is water,methylisobutyl ketone, methyl-THF, cyclohexanone, acetonitrile, acetone,methanol, ethanol, butanol, MTBE or mixtures thereof.

20. The process of either paragraph 18 or 19, wherein the isolatedlevulinic acid or formic acid and the filtrate are combined to provide afinal filtrate.

21. The process of paragraph 20, wherein the molar yield of levulinicacid is from about 50% to about 90%.

22. The process of paragraph 20, wherein the molar yield of formic acidis from about 50% to about 90%.

23. The process of any of paragraph 1 through 22, wherein the waterimmiscible solvent is methyl isobutyl ketone, ethyl levulinate, butyllevulinate, cyclohexanone, toluene, methyl-THF, methyl-tertiary butylether, methyl isoamyl ketone, hexane, cyclohexane, chloro-benzene,methylene chloride, dichloroethane, ortho-dichlorobenzene, diisobutylketone, 2,6-dimethyl cyclohexanone, tetrahydrofuran or mixtures thereof.

24. The process of any of paragraphs 1 through 23, wherein the aqueouslayer or final filtrate and water immiscible layers are separated.

25. The method of any of paragraphs 1 through 24, further comprising thestep of concentrating the water immiscible layer containing thelevulinic acid or formic acid to provide a concentrate.

26. The method of paragraph 25, wherein the concentration step isconducted under reduced pressure.

27. The method of paragraph 26, wherein the concentration step isconducted at an elevated temperature.

28. The method of paragraphs 25 or 26, wherein the water immisciblelayer is agitated.

29. The method of any of paragraphs 26 through 28, wherein the reducedpressure is from about 10 to about 700 torr.

30. The method of any of paragraphs 26 through 29, wherein the waterimmiscible layer was heated to about 20 to about 140° C.

35. The process of any of paragraphs 25 through 30, further comprisingthe step of subjecting the concentrate to wipe film evaporation toprovide purified levulinic acid.

36. The process of paragraph 35, wherein the levulinic acid had a purityof at least 95%.

37. The process of any of paragraphs 25 through 30, further comprisingthe step of treating the concentrate with a solid sorbent.

38. The process of paragraph 37, wherein the solid sorbent is/are piecesof wood, an ion exchange resin, optionally with a solvent, molecularsieves, optionally with a solvent, or activated carbon, optionally witha solvent.

39. The process of either paragraph 37 or 38, further comprising thesteps of removing the levulinic acid or formic acid from the solidsorbent by heat, pressure, or by rinsing with water, aqueous base or apolar solvent.

40. The process of any of paragraphs 1 through 24, wherein the processis conducted in a continuously-stirred tank reactor (CSTR) or aplug-flow reactor (PFR).

41. The process of paragraph 40, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to biomass is added tothe reactor over a period of 1 hour and an equivalent weight amount isremoved during the same time period.

42. The process of paragraph 41, wherein the biomass is fructose.

43. The process of either paragraphs 41 or 42, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of 1 hour and an equivalent weight amount is removed during thesame time period.

44. The process of paragraph 40, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to biomass is added tothe reactor over a period of time t and an equivalent weight amount isremoved during the same time period.

45. The process of paragraph 44, wherein the biomass is fructose.

46. The process of either paragraphs 44 or 46, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of time t and an equivalent weight amount is removed during thesame time period.

The following paragraphs provide for still further additional aspects ofthe present invention. In one embodiment, in a first paragraph (1), thepresent invention provides a process to prepare levulinic acid or formicacid, comprising the steps:

mixing sucrose, glucose, fructose containing material or mixturesthereof with and water to form a mixture,

heating the mixture at a temperature of from about 50° C. to about 280°C.;

cooling the mixture to provide an aqueous portion and solids;

isolating the aqueous portion from the solids; and

treating the aqueous portion with an water immiscible solvent to form anaqueous layer and a water immiscible layer, providing levulinic acid orformic acid in the water immiscible layer.

1a. The process of paragraph 1, wherein the mixture is heated from about80° C. to about 250° C.

1b. The process of paragraph 1, wherein the mixture is heated from about100° C. to about 220° C.

1c. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 100° C.

1d. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 90° C.

1e. The process of paragraph 1, wherein the mixture is heated from about50° C. to about 80° C.

1f. The process of paragraph 1, wherein the mixture is heated from about60° C. to about 80° C.

1g. The process of any of paragraphs 1 through 1f, wherein the mixtureis heated under pressure, wherein the pressure range is from about 10psi to about 1000 psi.

1h. The process of paragraph 1g, wherein the pressure range of fromabout 30 to about 500 psi.

1i. The process of paragraph 1g, wherein the pressure range if fromabout 50 to about 200 psi.

2. The process of paragraph 1, wherein the mixture contains from about 1to about 50 weight percent of sucrose, glucose, fructose containingmaterial or mixtures thereof.

3. The process of paragraph 2, wherein the fructose containing materialcomprises fructan, fructooligosaccharide, inulin, fructose, fructosecorn syrup or mixtures thereof.

4. The process of paragraph 2, wherein the sucrose, glucose, fructosecontaining material or mixtures thereof is present from about 5 to about30 weight percent.

5. The process of paragraph 1, wherein the acid is present from about 1to about 50 weight percent.

6. The process of any of paragraphs 1 through 5, wherein the mixture isheated for 60 minutes or less.

7. The process of paragraph 6, wherein the mixture is heated for 30minutes or less.

8. The process of any of paragraphs 1 through 7, further comprising thestep of mixing the mixture.

9. The process of any of paragraphs 1 through 8, wherein the isolationstep is filtration.

10. The process of paragraph 9, further comprising the step of treatingthe solids with a solvent to provide a filtrate.

11. The process of paragraph 10, wherein the solvent is water.

12. The process of either paragraph 10 or 11, wherein the aqueousportion and the filtrate are combined to provide a final filtrate.

13. The process of any of paragraph 1 through 12, wherein the waterimmiscible solvent is methyl isobutyl ketone, ethyl levulinate, butyllevulinate, cyclohexanone, toluene, methyl-THF, methyl-tertiary butylether, methyl isoamyl ketone, hexane, cyclohexane, chloro-benzene,methylene chloride, dichloroethane, ortho-dichlorobenzene, diisobutylketone, 2,6-dimethyl cyclohexanone, tetrahydrofuran or mixtures thereof.

14. The process of any of paragraphs 1 through 13, wherein the filtrateand water immiscible layers are separated.

15. The method of any of paragraphs 1 through 14, further comprising thestep of concentrating the water immiscible layer containing thelevulinic acid or formic acid to provide a concentrate.

16. The method of paragraph 15, wherein the concentration step isconducted under reduced pressure.

17. The method of paragraph 16, wherein the concentration step isconducted at an elevated temperature.

18. The method of paragraphs 15 or 16, wherein the water immisciblelayer is agitated.

19. The method of any of paragraphs 16 through 18, wherein the reducedpressure is from about 10 to about 700 torr.

20. The method of any of paragraphs 16 through 19, wherein the waterimmiscible layer was heated to about 20 to about 140° C.

21. The process of any of paragraphs 15 through 20, further comprisingthe step of subjecting the concentrate to wipe film evaporation toprovide purified levulinic acid.

22. The process of paragraph 21, wherein the levulinic acid had a purityof at least 95%.

23. The process of any of paragraphs 15 through 20, further comprisingthe step of treating the concentrate with a solid sorbent.

24. The process of paragraph 23, wherein the solid sorbent is/are piecesof wood, an ion exchange resin, optionally with a solvent, molecularsieves, optionally with a solvent, or activated carbon, optionally witha solvent.

25. The process of either paragraph 23 or 24, further comprising thesteps of removing the levulinic acid or formic acid from the solidsorbent by heat, pressure, or by rinsing with water, aqueous base or apolar solvent.

26. The process of any of paragraphs 1 through 15, wherein the processis a conducted in a continuously-stirred tank reactor (CSTR) or aplug-flow reactor (PFR).

27. The process of paragraph 26, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to sucrose, glucose, orfructose containing material is added to the reactor over a period of 1hour and an equivalent weight amount is removed during the same timeperiod.

28. The process of paragraph 27, wherein the biomass comprises fructose.

29. The process of either paragraphs 27 or 28, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of 1 hour and an equivalent weight amount is removed during thesame time period.

30. The process of paragraph 26, wherein the CSTR process is conductedwherein a ratio of about 2:1 to about 5:1 water to sucrose, glucose, orfructose containing material is added to the reactor over a period oftime t and an equivalent weight amount is removed during the same timeperiod.

31. The process of paragraph 30, wherein the biomass comprises fructose.

32. The process of either paragraphs 30 or 31, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of time t and an equivalent weight amount is removed during thesame time period.

The following paragraphs provide for yet still further additionalaspects of the present invention. In one embodiment, in a firstparagraph (1), the present invention provides a method to purifylevulinic acid comprising the steps:

dissolving levulinic acid in a solvent to provide a levulinic acidsolution;

contacting the levulinic acid solution with molecular sieves or a periodof time;

separating the molecular sieves from the levulinic acid solution; and

heating the sieves or applying reduced pressure to the sieves to releasepurified levulinic acid or treating the sieves with water, aqueous base,or a polar solvent to rinse the levulinic acid from the sieves.

2. The method of paragraph 1, wherein the molecular sieve size range isfrom about 2 angstroms to about 15 angstroms.

3. The method of either paragraph 1 or 2, wherein the weight ratio ofmolecular sieves to solvent is about 1:10 to 10:1.

4. The method of any of paragraphs 1 through 3, wherein theconcentration of levulinic acid in the levulinic acid solution is about1 to about 20 weight percent, more particularly from about 2 to about 15weight percent.

5. The method of any of paragraphs 1 through 4, wherein the solvent iscyclohexanone, methyl-tetrahydrofuran, toluene or methyl isobutylketone.

6. The method of any of paragraphs 1 through 5, wherein the purifiedlevulinic acid has a purity of at least 95%.

7. The method of any of paragraphs 1 through 6, wherein the color index(YI) of the purified levulinic acid has a color index of below 50 asmeasured by ASTM method E313.

The following paragraphs provide for further additional aspects of thepresent invention. In one embodiment, in a first paragraph (1), thepresent invention provides a method to purify levulinic acid comprisingthe steps:

dissolving from about 10 to about 50 weight percent levulinic acid in asolvent to provide a levulinic acid solution;

cooling the levulinic acid solution to about less than 15° C. to induceprecipitation of levulinic acid; and

collecting the precipitated levulinic acid.

2. The method of paragraph 1, wherein the solvent is methyl isobutylketone, cyclohexanone, or toluene.

3. The method of either of paragraphs 1 or 2, wherein the precipitatedlevulinic acid has a purity of at least 95%.

4. The method of any of paragraphs 1 through 3, wherein the precipitatedlevulinic acid has a color index of less than 50 as measured by ASTMmethod E313.

The following paragraphs provide for further additional aspects of thepresent invention. In one embodiment, in a first paragraph (1), thepresent invention provides a method to purify levulinic acid comprisingthe steps:

dissolving up to about 50 weight percent of levulinic acid in a solventwith the proviso that solvent is not water to provide a levulinic acidsolution; and

adding an aqueous base solution to the levulinic acid solution toprovide a levulinic acid salt precipitate.

2. The method of paragraph 1, wherein the base is an alkali metal or analkaline earth metal hydroxide or carbonate.

3. The method of paragraphs 1 or 2, wherein the weight percentage ofbase is from about 0.5 to about 5 equivalents based on the moles oflevulinic acid.

4. The method of any of paragraphs 1 through 3, wherein the solvent ismethyl isobutyl ketone, cyclohexanone, toluene or mixtures thereof.

5. The method of any of paragraphs 1 through 4, further comprising thestep of isolating the levulinic acid salt precipitate.

The following paragraphs also provide for further additional aspects ofthe present invention. In one embodiment, in a first paragraph (1), thepresent invention provides a method to prepare levulinic acid comprisingthe steps of:

combining levulinic acid, a biomass material, a mineral acid and lessthan 10 weight percent water to form a mixture, wherein the componentsequal 100 weight percent;

heating the mixture to a range of about 50° C. to about 280° C. toprovide a hydrolyzed mixture;

cooling the hydrolyzed mixture;

isolating solids from liquids; and

cooling the liquids to form precipitated levulinic acid.

1a. The process of paragraph 1, wherein the biomass comprises sludgesfrom paper manufacturing process; agricultural residues; bagasse pity;bagasse; molasses; aqueous oak wood extracts; rice hull; oats residues;wood sugar slops; fir sawdust; naphtha; corncob furfural residue; cottonballs; raw wood flour; rice; straw; soybean skin; soybean oil residue;corn husks; cotton stems; cottonseed hulls; starch; potatoes; sweetpotatoes; lactose; sunflower seed husks; sugar; corn syrup; hemp; wastepaper; wastepaper fibers; sawdust; wood; residue from agriculture orforestry; organic components of municipal and industrial wastes; wasteplant materials from hard wood or beech bark; fiberboard industry wastewater; post-fermentation liquor; furfural still residues; andcombinations thereof, a C5 sugar, a C6 sugar, a lignocelluloses,cellulose, starch, a polysaccharide, a disaccharide, a monosaccharide ormixtures thereof.

1b. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 80° C. to about 250° C.

1c. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 100° C. to about 220° C.

1 d. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 100° C.

1e. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 90° C.

1f. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 50° C. to about 80° C.

1g. The process of either paragraph 1 or 1a, wherein the mixture isheated from about 60° C. to about 80° C.

1h. The process of any of paragraphs 1 through 1g, wherein the mixtureis heated under pressure, wherein the pressure range is from about 10psi to about 1000 psi.

1i. The process of paragraph 1h, wherein the pressure range of fromabout 30 to about 500 psi.

1j. The process of paragraph 1i, wherein the pressure range if fromabout 50 to about 200 psi.

2. The method of any of paragraphs 1 through 1f, wherein the weightpercentage of levulinic acid is from about 50 to about 90.

3. The method of any of paragraphs 1 or 2, wherein the weight percentageof biomass is from about 5 to about 30.

4. The method of any of paragraphs 1 through 3, wherein the mineral acidweight percentage is from about 1 to about 20.

5. The method of any of paragraphs 1 through 4, wherein the weightpercentage of water is less than 8 percent.

6. The method of any of paragraphs 1 through 5, wherein the hydrolyzedmixture is cooled to range of below 20° C.

7. The method of any of paragraphs 1 through 6, wherein the liquids arecooled to range of from about 60° C. to about 10° C.

8. The method of any of paragraphs 1 through 7, wherein the biomasscomprises a C5 sugar, sucrose, a C6 sugar, a lignocelluloses, cellulose,starch, a polysaccharide, a disaccharide, a monosaccharide, a hard wooda soft wood, or mixtures thereof.

9. The process of any of paragraph 8, wherein the biomass is sucrose,fructose or glucose.

10. The process of any of paragraphs 1 through 9, wherein the mineralacid is sulfuric acid, phosphoric acid, hydrochloric acid or mixturesthereof.

The following paragraphs also provide for further additional aspects ofthe present invention. In one embodiment, in a first paragraph (1), thepresent invention provides a method to prepare levulinic acid comprisingthe steps of:

combining levulinic acid, a mineral acid and less than 10 weight percentwater to form a mixture, wherein the components equal 100 weightpercent;

mixing the mixture for a period of time at a temperature range of fromabout 50° C. to about 280° C.;

cooling the mixture to a temperature range of from about −30° C. toabout 5° C.; and

isolating solids from liquids to provide levulinic acid.

2. The method of paragraph 1, wherein the weight percentage of levulinicacid is from about 70 percent to about 95 percent.

3. The method of either paragraphs 1 or 2, wherein the mineral acidweight percentage is from about 5 percent to about 10 percent.

4. The method of any of paragraphs 1 through 3, wherein the weightpercentage of water from about 3 percent to about 8 percent.

5. The method of any of paragraphs 1 through 4, wherein the hydrolyzedmixture is cooled to range of from about −25° C. to about 10° C.

7. The method of any of paragraphs 1 through 5, wherein the mixture iscooled to range of from about −20° C. to about 5° C.

8. The process of any of paragraphs 1 through 7, wherein the mineralacid is sulfuric acid, phosphoric acid, hydrochloric acid or mixturesthereof.

The following paragraphs also provide for further additional aspects ofthe present invention. In one embodiment, in a first paragraph (1), thepresent invention provides a method to prepare levulinic acid or formicacid, comprising the steps: mixing up to 30 weight percent of a fructosecontaining material comprising fructan, fructooligosaccharide, inulin,fructose, fructose-glucose blended corn syrup, sucrose or mixturesthereof, up to 75 weight percent of an acid catalyst and at least 20weight percent water to equal 100 weight percent to form a mixture; andheating the mixture to a temperature of from about 50° C. to about 100°C. to provide levulinic acid or formic acid.

2. The process of paragraph 1, wherein the mixture comprises 40-75% ofan acid catalyst.

3. The process of paragraph 1, wherein the mixture comprises 50-70% ofan acid catalyst.

4. The process of any of paragraphs 1-3, wherein the acid catalyst issulfuric acid

5. The process of any of paragraphs 1-4 wherein the reaction is run forless than 480 minutes.

6. The process of any of paragraphs 1-4 wherein the reaction is run forless than 360 minutes.

7. The process of any of paragraphs 1-4 wherein the reaction is run forless than 120 minutes.

8. The process of any of paragraphs 1-4 wherein the reaction is run forless than 60 minutes.

9. The process of any of paragraphs 1-4 wherein the reaction is run forless than 30 minutes.

10. The process of any of paragraphs 1-4 wherein the reaction is run forless than 15 minutes.

11. The process of any of paragraphs 1-10 wherein the reaction is run ata temperature from about 50° C. to about 90° C.

12. The process of any of paragraphs 1-10 wherein the reaction is run ata temperature from about 50° C. to about 80° C.

13. The process of any of paragraphs 1-10 wherein the reaction is run ata temperature from about 60° C. to about 80° C.

The following paragraph provide for additional aspects of the presentinvention. In one embodiment, in a first paragraph (1), the presentinvention provides a process to prepare levulinic acid or formic acid,comprising the steps:

mixing up to 50 weight percent of a fructose containing materialcomprising fructan, fructooligosaccharide, inulin, fructose,fructose-glucose blended corn syrup, sucrose or mixtures thereof, up to75 weight percent of an acid catalyst and at least 20 weight percentwater to equal 100 weight percent to form a mixture; and

heating the mixture to a temperature of from about 50° C. to about 280°C. to provide levulinic acid or formic acid.

The following paragraphs also provide for further still additionalaspects of the present invention. In one embodiment, in a firstparagraph (1), applicable to any of the above noted paragraphs (noted as[051] through [0427], the process is conducted in a continuous additionbatch reactor.

2. The process of paragraph 1, wherein the continuous addition batchprocess is conducted wherein a ratio of about 2:1 to about 5:1 water tobiomass is added to the reactor over a period of 1 hour.

3. The process of paragraph 2, wherein the biomass is fructose.

4. The process of either paragraphs 1 or 2, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor over aperiod of 1 hour.

5. The process of paragraph 1, wherein the continuous addition batchprocess is conducted wherein a ratio of about 2:1 to about 5:1 water tobiomass is added to the reactor over a period of time t.

6. The process of paragraph 5, wherein the biomass is fructose.

7. The process of either paragraphs 4 or 5, wherein a ratio of about10:1 to about 15:1 water to mineral acid is added to the reactor overthe period of time t.

The following paragraphs also provide for further still additionalaspects of the present invention. In one embodiment, in a firstparagraph (1), applicable to any of the above noted paragraphs (noted as[051] through [0427], the biomass is added over a period of from about0.1 to about 40 hours, more specifically, 0.25 to 20 hours, morespecifically, 0.5 to 10 hours, and even more specifically, 0.75 to 5hours.

The following paragraphs also provide for further still additionalaspects of the present invention. In one embodiment, in a firstparagraph (1), applicable to any of the above noted paragraphs (noted as[051] through [0427], the formic acid and levulinic acid are extractedtogether using a first extraction solvent, or are extracted separately,using a first and a second extraction solvent. In another embodiment,the formic acid is removed from the reaction mixture by distillation,steam stripping or extraction prior to extracting the levulinic acid.

The invention will be further described with reference to the followingnon-limiting Examples. It will be apparent to those skilled in the artthat many changes can be made in the embodiments described withoutdeparting from the scope of the present invention. Thus the scope of thepresent invention should not be limited to the embodiments described inthis application, but only by embodiments described by the language ofthe claims and the equivalents of those embodiments. Unless otherwiseindicated, all percentages are by weight.

In one aspect, the invention is directed to a process to makecrystallizable levulinic acid (“LA”) from sugar solutions.

Hydrolysis of a 1-3 Molar solution of sucrose, glucose, fructose, orblends of the aforementioned, specifically fructose and sucrose, occursin a batch or continuous reactor, specifically a continuous reactor. Inone embodiment the method includes the following steps followinghydrolysis of a 1-3 Molar solution of sucrose, glucose, fructose, orblends of the aforementioned:

(a) Filtration of solids from hydrolysate mixture.

(b) Water or extraction solvent wash of solids (optional).

(c) Extraction of LA and formic acid from aqueous hydrolysate into anextraction solvent.

(d) Removal of extraction solvent by distillation.

(e) Thin-film evaporation of LA.

(f) Crystallization of LA

(g) recovery of formic acid.

The process allows fast reaction time, easy to handle char byproduct,good yields, no neutralization step (optional), efficient extraction anddistillation to afford a crystallizable LA product.

A few processes are known to make LA from sugar, but little is known onhow to remove the LA and formic acid from the reactor and purify it fromthe hydrolysate. The disclosed process produces approximately 97% purityLA that crystallizes.

Unless otherwise noted, the concentration of sulfuric acid used is96-98%.

Example 1

Into a 1 L hastelloy parr reactor 135.12 g fructose (94% purity, 0.75mol), 500 mL DI water, and 38.17 g sulfuric acid were charged. Thereactor was sealed and the reaction mixture was heated up to atemperature of 150° C. while stirring at 52 RPM. Once the reactionmixture reached a temperature of 150° C., the mixture was held at thattemperature for 1 hour. After the 1 hour reaction time the heat wasturned off and the heating mantle was lowered and the reactor was cooledusing an ice water bath. Once the reactor was cooled it was dismantledand the reaction mixture was filtered through a 0.45 μm filter usingvacuum filtration in order to remove the char from the liquid. Theliquid was analyzed by HPLC and found to contain 9.9 wt % levulinicacid. The liquid is referred to as “hydrolysate”.

Into a 1 L separatory funnel 300.10 g hydrolysate and 300.07 g Methylisobutyl ketone (MIBK) were charged. The separatory funnel was shaken inorder to mix everything together and then the mixture was allowed tophase separate. The bottom aqueous layer was drained out of the bottomof the separatory funnel and collected in a beaker. The top layer waspoured out of the top of the separatory funnel and into a 2-neck 1 Lround bottom flask. The bottom layer was then placed back into theseparatory funnel and another 300.36 g MIBK were used for the secondextraction. The mixture was shaken and allowed to phase separate again.The bottom layer was drained and discarded. The top layer was poured outof the top of the separatory funnel into the 2-neck 1 L round bottomflask containing the previous MIBK-extract.

The 2-neck 1 L round bottom flask (RBF) was situated into a heatingmantle and equipped with a magnetic stir bar, thermocouple, vigreuxcolumn, short path condenser, and a 1 L collection flask. The mixturewas stirred at 600 rpm and the vacuum was kept between 15-30 torr. Overthe course of the distillation the temperature of the pot was slowlyincreased until a maximum temperature of 70° C. was reached. The MIBKwas distilled away from the mixture, the crude levulinic acid (LA)mixture left in the pot was a very dark brown color.

The crude LA was purified by wipe film evaporation (WFE). The crude LAwas placed into a reservoir and degassed. The heater was turned on andset to 70° C. and the vacuum was set to 0.25-0.3 Torr. Once atemperature of 70° C. was reached the blades were turned on and thecrude LA was slowly fed into the WFE. Dark black material was collectedin the heavy fraction and light yellow material was collected in thelight fraction. Once all of the material had passed through the WFE, thevacuum, heat and blades were shut off and the light fraction, LA, wasanalyzed by GC-FID. The GC-FID results showed that the LA was 95% pure.A small sample of this LA was put into a scintillation vial and cooledto 5° C., and it crystallized. This light yellow LA was redistilled byWFE a second time. This time the temperature was set to 65° C. and thevacuum was still at 0.25-0.3 Torr. Again, the dark material wascollected in the heavy fraction and a faint red material was collectedin the light fraction. Once all of the LA had gone through the WFE itwas shut down and the light fraction was analyzed by GC-FID. The GC-FIDresults of the LA after going through the WFE a second time showed thatthe LA was 97% pure. This LA was cooled to 5° C. The entire samplecrystallized, indicating good quality levulinic acid.

Use of fructose as a feedstock for the production of levulinic acid isknown in the art. HCl has been used as a catalyst to make levulinicacid. HCl is a very corrosive catalyst and creates the possibility ofgenerating chlorinated organic compounds, so this is not a good option.

Zeolites have been used as catalysts for the production of LA. Thezeolites are typically used in high concentrations, and presumably wouldfoul due to the formation of solid humin substances during theconversion of fructose to LA. This catalyst cost would not beeconomically viable for the production of LA. Also, U.S. Pat. No.7,317,116 describes the use of fructose or high fructose corn syrup tomake levulinic acid using heterogeneous cation exchange resin catalystsand polyethylene glycol solvents. The use of heterogeneous catalysts toproduce LA from biomass or sugars would also have the problem of foulingby the formation of soluble polymeric and insoluble polymericsubstances, known as humins. Additionally, the time of the reactionrequired to convert fructose to LA as described in U.S. Pat. No.7,317,116 was 4-18 h, which would be much too long for an industrialcontinuous process.

Herein, a new method is described for the conversion of fructose orfructose-containing feedstocks into levulinic acid and formic acid. Theprocess allows up to 30 wt % feedstock and from about 4 to about 60 wt %mineral acid, such as sulfuric acid, to be used in an aqueous reactionmixture, while producing >50 mol % LA in less than 60 minutes ofreaction time, preferably less than 30 minutes of reaction time, andmore preferably less than 20 minutes of reaction time.

In another embodiment, this process can be backwards integrated into acellulose or ligno-cellulose producer or bio-refinery.

In another embodiment, the use of washing the produced humin substanceswith a solvent or water, or a combination of both, is an addedbeneficial method to produce a higher mass recovery of LA and formicacid.

Example 2

1 Mol/L D-Fructose (15 mL) was prepared by diluting 2.44 g ofcrystalline D-Fructose (93.5% purity, 6.5% moisture, Aldrich) up to 15.0mL with DI water. The 15.0 mL was transferred to a 3 oz. empty highpressure, high temperature reaction vessel, and concentrated sulfuricacid (407 μL) was added. The reaction vessel was capped using a Teflonsleeve, an o-ring, rubber washer and a stainless steel plug. The reactorwas securely closed with stainless steel couplings. The reaction vesselwas placed into a 180° C. hot oil bath to reach an internal temperatureof around 160° C. After a specified reaction time, the reaction vesselwas then removed from the hot oil and placed in a room temperature waterbath for 1 minute to begin cooling. Following the room temperature waterbath, the reactor was placed in an ice water bath to quench thereaction. Once the reactor vessel had cooled, it was opened, and thecontents were filtered, weighed, and then analyzed by HPLC. The huminsolids that formed during the reaction were extracted with DI water andthe LA in the “wash” sample was recovered and analyzed by HPLC andweighed separately to obtain the yield. The two yields of LA were addedtogether to obtain the final mol % yield of LA relative to the initialmoles of fructose charged in the feed. The final results are displayedin Table I.

Examples 3-4

The procedure outlined in Example 2 was repeated, except that the feedconcentration of fructose and acid catalyst was varied, as well as, thetemperature of the reaction.

TABLE I Wt % LA Yield Improvement Wt % Molar Molar after Wt % SulfuricFructose Yield Yield Washing Fructose acid in Max. Time Conversion of LAof FA Solid Example in Feed feed Temperature (min) (%) (%) (%) Humins 213.6 4.7 143° C. 50 100 54 66 16 3 18.9 5.5 156° C. 30 100 63 76.9 12 423.5 5.5 160.1° C.   30 100 62 79 15

As can be seen from Table I, fructose can be hydrolyzed completely inless than 60 minutes of reaction time to afford up to 63 mol % yield and79 mol % yield of formic acid (FA). Also, extracting LA from the solidhumin material resulted in >10 wt % yield improvement of LA in all ofthe examples.

Utilizing High Fructose Corn Syrup, inulin, oligomeric fructan polymers,and the like are also be useful in this invention.

Another process of this invention involves the pretreatment of glucoseto obtain >70% conversion to fructose directly before the fructose ishydrolyzed to LA and formic acid (FA). The process involves glucoseconversion to fructose (without crystallization of the fructose), thefructose then feeds into a solution with water and sulfuric acidcatalyst to form LA and FA in less than 60 minutes of reaction time.This pre-treatment of the glucose or sugar feedstock may beenzymatically catalyzed or chemically catalyzed to afford >70%conversion of the glucose or “sugar” to fructose. Methods of glucose tofructose conversion are generally known in the art.

The glucose and “sugar” polymer mixture may be obtained by the enzymaticdegradation of starch, maltose, or the like, or alternatively, by thehydrolytic or catalytic degradation of cellulose to glucose. The glucoseobtained from these reactions may also be obtained from aligno-cellulosic feedstock.

Also, this process can be attached to a bio-refinery, whichdepolymerizes cellulose or ligno-cellulose into glucose for ethanolproduction, but instead of producing 100% ethanol, some of the processstreams containing crude or purified glucose are subsequently convertedinto fructose and then to LA and FA.

In a typical biomass process, biomass is converted into levulinic acid(LA) and formic acid (FA) by a strong-acid catalyst in a dilute, aqueoussystem. The LA and FA are then first extracted into a solvent phase toremove the LA and FA from the aqueous phase containing the strong-acidcatalyst. The solvent may be, for example, methyl-isobutyl ketone(MIBK), methyl isoamyl ketone (MIAK), cyclohexanone, o, m, andpara-cresol, substituted phenols, for example, 2-sec butyl phenol,C4-C18 alcohols, such as n-pentanol, isoamyl alcohol, n-heptanol,2-ethyl hexanol, n-octanol, 1-nonanol, cyclohexanol, methylene chloride,1,2-dibutoxy-ethylene glycol, acetophenone, isophorone,o-methoxy-phenol, methyl-tetrahydrofuran, tri-alkylphosphine oxides(C4-C18) and ortho-dichlorobenzene and mixtures thereof. Once the LA andFA is extracted into the solvent, the usual way of purification of theLA and FA is by removing the solvent through energy-intensivedistillation followed by distillation of the LA, another energyintensive step which may lead to side-products and yield losses.

One novel way of purifying the LA from the extractive solvent is toremove the LA by the use of an adsorbents, like molecular sieves, basicalumina, silica gel, or the like.

Example 5

A 10.22 gram solution of levulinic acid (4.8 wt %) in cyclohexanone wasweighed in a 125 mL Erlenmeyer Flask. 10.05 of 3 A Molecular Sieves wasadded to the flask. The flask was sealed with parafilm to preventevaporation of the solvent. The mixture was aged overnight (>12 h) atroom temperature. A sample of the liquid was withdrawn from the flaskand analyzed by HPLC. The amount of LA in the final liquid was found tobe 3.7 wt %, indicating that approximately 0.11 g of LA had beenadsorbed by the molecular sieves.

TABLE 2 Examples 6-16 were repeated as described in Example 5, exceptthat different solvents and different sizes of molecular sieves wereused according to Table 2. Size of Molec- g of g of % LA in % LA Exam-ular Mol sol- Solvent solvent removed ple Sieves Sieves vent Type(Initial) (Final) 5 3A 10.05 10.22 cyclohex- 4.8 23 anone 6 4A 10 10.01cyclohex- 4.8 10 anone 7 5A 10 10.06 cyclohex- 4.8 21 anone 8 3A 10.0310.03 methyl-THF 4.4 11 9 4A 10.06 10.04 methyl-THF 4.4 9 10 5A 10.110.02 methyl-THF 4.4 14 11 3A 10.02 10.04 toluene 5.2 42 12 4A 10.0210.11 toluene 5.2 37 13 5A 10.04 10.13 toluene 5.2 40 14 3A 10.02 10.03MIBK 4.0 35 15 4A 10.01 10.06 MIBK 4.0 17.5 16 5A 10.09 10.02 MIBK 4.032.5

As can be seen from the data, LA may be removed from typical hydrolysateextraction solvents by molecular sieves. The 3 A and 5 A size molecularsieves seem to provide a more selective removal of levulinic acid invirtually all solvent systems. This provides a unique and alternativepathway to remove levulinic acid in a biomass-type hydrolysis systeminvolving an extraction solvent.

In other examples, basic alumina, silica gel, activated carbon, biomasschar, zeolites, activated clays, anion exchange resins, and ion exchangeresins, may be used to adsorb levulinic acid from an extractionsolvents.

In a typical biomass process, biomass is converted into levulinic acid(LA) and FA by a strong-acid catalyst in a dilute, aqueous system.However, instead of using water as the solvent, one embodiment, it wouldbe beneficial if the solvent was actually one of the products, forexample, levulinic acid or formic acid.

This portion of the invention describes how the hydrolysis of biomassmay be conducted in formic or levulinic acid. If the hydrolysis ofbiomass is conducted in levulinic acid, then once the reaction isfinished, filtered to remove char, and cooled to room temperature,levulinic acid may form a crystalline solid. This solid form oflevulinic acid offers a unique advantage of purification of the LA frombiomass.

In a typical hydrolysis of biomass, 2-20 wt % sulfuric acid is used asthe catalyst, and the amount of water used in the hydrolysis is between60-95 wt %. In this invention, the majority of the water is removed andreplaced with levulinic acid, which enables crystallization of the finalLA product by cooling the hydrolysate solution comprising water, LA, andsulfuric acid.

Experimental-Crystallization of LA in a Hydrolysis Mixture Example 17

A mixture containing 10 wt % sulfuric acid, 87 wt % levulinic acid, and3 wt % water was made in a 20 mL scintillation vial. The vial was cooledin a refrigerator at 5° C. overnight. After 24 h, crystals had formed inthe vial, indicating that the levulinic acid had crystallized out ofsolution.

Examples 18-23 were repeated as described in Example 17, except thatdifferent amounts of LA, sulfuric acid, and water were used in theexperiments.

TABLE 3 Crystals Sulfuric Acid DI Water present after Example (wt %) LA(wt %) (wt %) cooling (4 d) 17 10 87 3 yes 18 7.5 87 5.5 yes 19 5 87 8no 20 5 92 3 yes 21 10 77 13 no 22 10 67 23 no

As can be seen from the data, LA may be crystallized out from cooling asolution of LA, water, and a strong acid catalyst. This could be veryadvantageous for enabling a process to produce and purify LA from thestrong acid catalyzed degradation of furfuryl alcohol, sugars, orligno-cellulosic biomass.

Example 23

The reaction is carried out by adding 640 g of levulinic acid and 50 gof sulfuric acid (96+%, Aldrich), 100 g fructose (crystalline, 93+%purity, Aldrich), and 6 g of DI water to a 1 L Hastelloy autoclaveequipped with a magnetically couple overhead stirrer. The contents arepurged with nitrogen and heated to 160° C. for 1 h. The contents arecooled to 40° C. and filtered. Then, the contents are cooled below 10°C. and allowed to crystallize. The crystalline product is filtered andsubsequently purified.

Example 24

The reaction is carried out by adding 640 g of levulinic acid and 50 gof sulfuric acid (96+%, Aldrich), 100 g furfuryl alcohol (crystalline,93+% purity, Aldrich), and 25 g of DI water to a 1 L Hastelloy autoclaveequipped with a magnetically couple overhead stirrer. The contents arepurged with nitrogen and heated to 160° C. for 1 h. The contents arecooled to 40° C. and filtered. Then, the contents are cooled below 10°C. and allowed to crystallize. The crystalline product is filtered andsubsequently purified.

Example 25

The reaction is carried out by adding 640 g of levulinic acid and 50 gof sulfuric acid (96+%, Aldrich), 100 g sucrose (crystalline, 97+%purity, Aldrich), and 8 g of DI water to a 1 L Hastelloy autoclaveequipped with a magnetically couple overhead stirrer. The contents arepurged with nitrogen and heated to 160° C. for 1.5 h. The contents arecooled to 40° C. and filtered. Then, the contents are cooled below 10°C. and allowed to crystallize. The crystalline product is filtered andsubsequently purified.

Example 26

The reaction is carried out by adding 640 g of levulinic acid and 50 gof sulfuric acid (96+%, Aldrich), 100 g glucose (crystalline, 98+%purity, Aldrich), and 6 g of DI water to a 1 L Hastelloy autoclaveequipped with a magnetically couple overhead stirrer. The contents arepurged with nitrogen and heated to 160° C. for 2.5 h. The contents arecooled to 40° C. and filtered. Then, the contents are cooled below 10°C. and allowed to crystallize. The crystalline product is filtered andsubsequently purified.

Example 27

The reaction is carried out by adding 640 g of levulinic acid and 50 gof sulfuric acid (96+%, Aldrich), 100 g soft wood (pine, Home Depot),and 20 g of DI water to a 1 L Hastelloy autoclave equipped with amagnetically couple overhead stirrer. The contents are purged withnitrogen and heated to 160° C. for 1 h. The contents are cooled to 40°C. and filtered. Then, the contents are cooled below 10° C. and allowedto crystallize. The crystalline product is filtered and subsequentlypurified.

In a typical biomass process, biomass is converted into levulinic acid(LA) and FA by a strong-acid catalyst in a dilute, aqueous system. Thelevulinic acid and optionally the formic acid, is then first extractedinto a solvent phase to remove the levulinic acid and/or the formic acidfrom the aqueous phase containing the strong-acid catalyst. The solventmay be, for example, methyl-isobutyl ketone (MIBK), methyl isoamylketone (MIAK), cyclohexanone, o, m, and para-cresol, substitutedphenols, for example, 2-sec butyl phenol, C4-C18 alcohols, such asn-pentanol, isoamyl alcohol, n-heptanol, 2-ethyl hexanol, n-octanol,1-nonanol, cyclohexanol, methylene chloride, 1,2-dibutoxy-ethyleneglycol, acetophenone, isophorone, o-methoxy-phenol,methyl-tetrahydrofuran, tri-alkylphosphine oxides (C4-C18) andortho-dichlorobenzene and mixtures thereof or the like, morespecifically, methyl isoamyl ketone (MIAK), o, m, and para-cresol,phenol, isoamyl alcohol, n-hexanol, n-heptanol, 2-ethyl hexanol,o-methoxy-phenol, 2-4 dimethyl phenol, methyl isobutyl carbinol, andmixtures thereof or the like, and even more specifically, o, m, andpara-cresol, isoamyl alcohol, neopentyl alcohol, methyl isobutylcarbinol, and mixtures thereof or the like. Once the LA is extractedinto the solvent, the usual way of purification of the LA is by removingthe solvent through energy-intensive distillation followed bydistillation of the LA, another energy intensive step which may lead toside-products and yield losses.

One novel way of purifying the LA from the extractive solvent is todistill off a portion of the solvent, then allow the LA to crystallizeout of the solvent by cooling. LA is usually diluted to about 1-20 wt %in the hydrolysate prior to extraction, and after extraction, theconcentration of LA in the solvent can be from 0.5-50 wt %, preferablyfrom 1-45 wt %, and more preferably, from 2-40 wt %. The solvent may bedistilled away from LA in order to concentrate the LA. The followingexamples describe the invention.

Example 28

A 10% solution of levulinic acid in MIBK was made in a 20 mLscintillation vial. The vial was sealed and put into a freezer at −15°C. The solution remained clear and homogenous indicating that nocrystallization took place.

Examples 29-39 were repeated as described in Example 28, except thatdifferent solvents and different concentrations of LA were usedaccording to Table 4.

TABLE 4 LA Concentration Crystallization Example Solvent (wt %) at −15°C. 29 MIBK 20 no 30 MIBK 50 yes 31 cyclohexanone 10 no 32 cyclohexanone20 no 33 cyclohexanone 50 no 34 toluene 10 yes 35 toluene 20 yes 36toluene 50 yes 37 methyl THF 10 no 38 methyl THF 20 no 39 methyl THF 50no

As can be seen from the data, LA may be crystallized out from cooling asolution of MIBK that contains >20% LA. Also, Examples 34-36 demonstratethat LA may be crystallized from a solution of toluene that is cooled.

Another way to purify levulinic acid in an extraction solvent is byadding a base, for example, sodium hydroxide to form the metal salt,which would precipitate from the extraction solvent.

Example 40

2.52 g (0.02 mol) of levulinic acid and 47.57 g methyl isobutyl ketone(MIBK) were added to a 250 mL beaker and mixed thoroughly untilhomogeneous. To this mixture, 1.75 g of a 50/50 wt % sodium hydroxidesolution was added. As soon as the sodium hydroxide was added, a whiteprecipitate formed. A magnetic stir bar was placed into the beaker andput onto a stir plate to stir for a few minutes. With stirring, itappeared as though more precipitate formed. The precipitate was thenfiltered out using vacuum filtration and a 0.45 μm filter. A smallamount of the precipitate was put into a GC vial and dissolved withwater and then run on the HPLC to be analyzed. The analysis showed thatthe sodium salt of levulinic acid was synthesized.

Example 41

A small portion of the 5% levulinic acid solution in MIBK made inExample 40 was added into a saturated solution of calcium hydroxide inwater. Two liquid phases formed that were cloudy at first, and thenbecame transparent upon stirring at room temperature in a 250 mL beaker.No precipitate had formed.

Example 42

An MIBK solution containing 4% levulinic acid, 1% formic acid, 0.05%H₂SO₄, and 1% water was placed into a 250 mL beaker. A 50-50 wt %solution of sodium hydroxide in water was added to neutralize the acidspecies. Upon addition, a gel-like substance formed at the bottom of theflask. No precipitate formed.

Example 43

An MIBK solution containing 4% levulinic acid, 1% formic acid, and 0.05%H2SO4 was placed into a 250 mL beaker. A 50-50 wt % solution of sodiumhydroxide in water was added to neutralize the acid species. Uponaddition, white precipitate formed indicating that the sodium salt oflevulinic acid had formed.

Example 44

Approximately 1% water was added to Example 16, and the precipitateturned into a gel-like substance. Thus, having less than 1% water in theentire crude mixture is advantageous for the formation of solid sodiumlevulinate in a typical hydrolysate solution of 4% LA in MIBK solvent.

In another aspect, the present invention is directed to methodsincluding the use of organic or inorganic, hydrophobic co-solvents forthe preparation of LA from the hydrolysis of biomass. In one embodiment,the invention includes charging a co-solvent and optionally, aco-catalyst, for the purposes of improving the overall yield oflevulinic acid from biomass. The biomass may be lignocellulosic,cellulosic, starch-based, or sugar-based (monomeric, dimeric, oroligomeric sugars). The process has the advantage of simultaneouslymaking and extracting HMF and or levulinic acid from biomass.

Example 45

The reaction was carried out by adding 300 g of water and 15.02 g ofsulfuric acid (96+%, Aldrich), 54.07 g fructose (crystalline, 93+%purity, Aldrich), and 300 g of methyl-THF to a 1 L three-neck flask thatwas equipped with a magnetic stirrer and a reflux condenser. Thecontents were purged with nitrogen continuously and allowed to refluxfor 6 h. Aliquots were removed from the flask as a function of time tomeasure the composition in both layers. Analysis of the reaction mixtureshowed formation of HMF and the absence of levulinic acid.

Example 46

Example 45 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 47

Example 45 is repeated except that methyl isobutyl ketone was usedinstead of methyl-THF.

Example 48

Example 47 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 49

Example 45 is repeated except that cyclohexanone was used instead ofmethyl-THF.

Example 50

Example 49 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 51

Example 46 is repeated except that toluene was used instead ofmethyl-THF.

Example 52

Example 51 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 53

Example 45 is repeated except that 4-sec-butyl phenol was used insteadof methyl-THF.

Example 54

Example 53 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 55

Example 45 is repeated except that 1,2-dichloro-benzene was used insteadof methyl-THF.

Example 56

Example 55 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 57

Example 45 is repeated except that m-cresol was used instead ofmethyl-THF.

Example 58

Example 57 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 59

Example 45 is repeated except that tri-octyl phosphine oxide was usedinstead of methyl-THF.

Example 60

Example 59 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 61

Example 45 is repeated except that tri-butyl phosphate was used insteadof methyl-THF.

Example 62

Example 61 is repeated except that 13 g of para-toluene sulfonic acidwas added to the mixture.

Example 63

Example 45 is repeated except that sucrose was used instead of fructose.

Example 64

Example 45 is repeated except that 20 g of naphthalene sulfonic acid wasadded to the mixture.

Example 65

Example 45 is repeated except that 20 g of camphor sulfonic acid wasadded to the mixture.

Example 66

Example 45 is repeated except that 10 g of benzene sulfonic acid wasadded to the mixture.

Any of examples 45-66 could be repeated at higher pressure in aHastelloy, Zirconium, or glass-lined steel autoclave.

Any of the examples 45-66 could be repeated using glucose, soft wood,hard wood, starch, or cellulose.

Any of the examples 45-66 could be repeated using furfuryl alcohol orhydroxymethyl furfural.

Triflic acid, hydrochloric acid, hydrobromic acid, hydroiodic acid,nitric acid, phosphoric acid, boric acid, hydrofluoric acid, perchloricacid and mixtures thereof may be used instead of sulfuric acid ifdesired.

Example 67

After a sufficient time of reaction, the organic solvent layer isremoved from the aqueous layer by a decanter or centrifuge. Then, acertain quantity of aqueous sodium hydroxide is added to the organicmixture until a precipitate forms. The precipitate is filtered,acidified, and crystallized to afford >95% purity levulinic acid. Theorganic solvent is re-used in the process after distillation.

Example 68

After a sufficient time of reaction, the organic solvent layer isremoved from the aqueous layer by a decanter or centrifuge. Then, thesolvent is cooled down to <10° C. The precipitate is filtered andcrystallized to afford >95% purity levulinic acid. The organic solventis re-used in the process after distillation.

Continuously Stirred Tank Reactor (CSTR) Operations:

A stirred, 300 ml Parr Autoclave, of Hastelloy construction, was used toinvestigate a continuous process for the acid-catalyzed production oflevulinic and formic acids from carbohydrate sugars. Variable feed flowrates, coupled with controlled reactor volumes, were used to obtainvarious residence times in the autoclave. This reaction producesinsoluble by-products in addition to formic and levulinic acids.Therefore, control of product flow from the reactor was unsuccessfulusing standard laboratory techniques due to rapid plugging of regulatorsand other flow-restricting devices. This was overcome by using thepressure in the autoclave to periodically blow a controlled quantity ofreactor contents out of the autoclave and into a receiver through atwo-way valve connected to a dip tube of a prescribed length (depth)inside the autoclave. The depth of the dip tube controlled the reactorvolume around 180 ml. Continuously feeding reactants into the autoclaveat 3.0 ml/minute and rapidly pulsing the two-way valve full-open andfull-closed every 6.6 minutes removed approximately 20 g of sample,giving a residence time in the reactor of approximately 60 minutes.After liquid is removed down to the control volume, some gas is allowedto also escape, thereby “blowing” the lines clear of liquid. Thediameter of the dip tube is selected to allow removal of both the liquidand solid components of the reaction mixture without plugging the lines.¼Inch lines proved sufficient for this purpose. All outlet lines requireinsulation/heating to maintain them at the same temperature as thereactor. This prevents premature precipitation of solids from thesamples which can cause plugging. Reactants are fed into the autoclaveat controlled flow rates using an Eldex pump (A-120 VS).

Example 69 CSTR Run Using Corn Sweet 90

Corn Sweet 90 is a high-fructose syrup (90% fructose, 8.5% glucose, 1.5%oligiomeric sugars) supplied by ADM. It contains 77% solids. 360 g ofthis syrup was dissolved in 1.0 liter of 0.5M sulfuric acid and used asfeed to the reactor. The autoclave was filled with 200 ml of distilledwater and heated to 160° C. Internal pressure reached approximately80-85 psig. After reaching reaction temperature, volume control wasinitiated by pulsing the valve and removing approximately 20 g of water.The pressure drops approximately 5-8 psig during sampling. Continuousfeed was then initiated at 3 ml/minute with sampling occurring every 6.6minutes. The weight of the samples through the run averagedapproximately 20 g. The samples were dark reddish-brown in appearanceand a small amount of solids precipitated out of solution as the samplescooled. Analysis of a sample taken 3 hours after initiation of CornSweet feed was analyzed using Liquid Chromatography (Agilent HPLC;Restek Ultra C18 Column-15 cm; 98% 2.5 pH Phosphate Buffer/2%acetonitrile; 0.5 ml/minute Eluent flow at room temperature; UV/RIdetector). The sample contained 4.7% formic acid, 9.6% levulinic acidand 0.12% hydroxymethylfurfural (HMF). The low concentration of HMF isan excellent indicator of reaction completion. When the reaction wasterminated, the autoclave was opened and 27.49 g of black solids wereremoved.

CSTR Runs Using Sucrose and Sucrose/NORIT Activated Carbon Example 70

An attempt was made to execute a continuous run using 1.M sucrose in0.5M sulfuric acid at 160° C. This reaction with sucrose proveddifficult to execute. Outlet sample lines plugged quickly andinsufficient time occurred to achieve steady state in a continuous mode.Sucrose feed was terminated and the reaction was allowed to run tocompletion (1 hour) in batch mode. After the end of the run, the reactorwas cooled and opened to find it full of solids. The solids adheredstrongly to all the stainless steel internals inside the reactor(agitator, thermo well, dip tubes but not to the Hastelloy surfaces ofthe reactor body.) It appeared that the solids were nucleating and thengrowing on all the stainless steel surfaces of the reactor internals.

Example 71

A second run was initiated under the same conditions as those describedin Example 75 except 5 weight % of NORIT Activated Carbon (PAC-200;BA#M-1620) was added to the autoclave to begin with. This was an attemptto give the solids something else on which to nucleate and adhere. A onehour batch run was completed and sampled using the two-way blow-downvalve. This time, in contrast to the “NORIT-free” run, the sample waseasily removed from the reactor. As the sample cooled, no separatesolids were observed coming out of solution. The NORIT that exited fromthe reactor in the sample settled to the bottom of the sample receiverand it appeared that the solids that usually precipitate from solutionupon cooling were adsorbed on the NORIT. When the autoclave was cooledand opened, the amount of solids usually found adhering to all thereactor internals were markedly reduced. It, again, appeared that theNORIT had allowed the reaction solids to adsorb/adhere to the activatedcarbon. This will clearly improve the operability of the reaction,particularly when using sugars that are more prone to form solids inthis reaction.

Example 72

Into a three neck 250 mL round bottom flask charged 130.01 g deionizedwater, 23.52 g (0.13 mol) D-fructose, and 38.30 g (0.39 mol) sulfuricacid. The round bottom flask was equipped with a magnetic stir bar,thermocouple, condenser, and glass stopper. The stir plate was set tostir at a rate of 550 RPM and the fructose quickly dissolved. Themixture changed from clear and colorless to clear and a peach color. Theheat was turned on and set to a temperature of 60° C. The reaction wasleft to react for two hours and samples were taken and analyzed by HPLC.After the two hours, the reaction was shut down.

Time (minutes) Temperature ° C. % HMF (HPLC) 120 59.8 0.308

Example 73

Into a three neck 250 mL round bottom flask charged 13.08 g deionizedwater, 23.48 g (0.13 mol) D-fructose, and 31.23 g (0.39 mol)polyphosphoric acid. The round bottom flask was equipped with a magneticstir bar, thermocouple, condenser, and glass stopper. The stir plate wasset to stir at a rate of 550 RPM and the fructose quickly dissolved. Theheat was turned on and set to a temperature of 60° C. The reaction washeld at 60° C. for two hours and then the temperature was increased to80° C. The reaction was held at 80° C. for one hour and a half and thenthe temperature was increased to 100° C. The reaction was held at 100°C. for two hours and then the reaction was shut down. Samples were takenthroughout the entire reaction and analyzed by HPLC.

Time (minutes) Temperature ° C. % HMF (HPLC) 410 99.7 1.747

Example 74

Into a three neck 250 mL round bottom flask charged 130.12 g deionizedwater and 23.49 g (0.13 mol) D-fructose. The round bottom flask wasequipped with a magnetic stir bar, thermocouple, condenser, and glassstopper. The stir plate was set to stir at a rate of 550 RPM and thefructose quickly dissolved. Once the fructose was dissolved, 38.29 g(0.39 mol) sulfuric acid was added into the flask. The heat was turnedon and set to a temperature of 80° C. The reaction was held at 80° C.for two hours and then the temperature was increased to 100° C. Thereaction was held at 100° C. for four hours and fifteen minutes and thenthe reaction was shut down. Samples were taken throughout the entirereaction and analyzed by HPLC.

% HMF % LA % FA Time (minutes) Temperature ° C. (HPLC) (HPLC) (HPLC) 385100.0 0.007 6.28 2.607

Sugar Solution Preparation

Sugar-solution I is a mixture of 90 wt % fructose, 8.5 wt % glucose, and1.5 wt % sucrose. This mixture was dissolved in water to obtain ahomogeneous solution that was 1.5 Moles of Sugar-solution I/Liter.

Example 75

1.5 Molar Sugar-solution I (715 g) and concentrated Sulfuric Acid (35.75g) was added to a 1 L Hastelloy reactor (Parr Model 4530 Reactor). TheParr reactor was assembled and securely closed. Mixing in the reactorbegan and set to 100 rpm. The initial time, temperature, and pressure ofthe reactor was noted. An electrical heating mantel was then placedaround the reactor and set to 160 C. Once the temperature inside of thereactor reached 160 C, it was held for 1 hr. After 1 hr, an ice-waterbath was placed around the Parr reactor to immediately begin cooling.When the temperature of the Parr reactor was below 30 C, it was openedand the contents of the reactor were removed and analyzed by HPLC. Anysolids that formed during the reaction were filtered from the reactionmixture, rinsed with water and dried in a vacuum oven to obtain theweight of total solids.

The HPLC results showed 6.7% of Levulinic acid and 2.9% Formic acidformed. The percent solids were 4.5%.

Examples 76-78

Further reactions were performed under the same procedure as Example 75.Table 5 outlines the reactions, and HPLC results.

TABLE 5 1 wt % Liquid 95% Paratoluene Liquid Hydrolysate SulfiricSulfonic Hydrolysate Recovered + Top Bottom Dry Solids Molar Corn AcidAcid Recovered Water Layer Layer Recovered LA wt % Sweet 90 Solvent (g)(g) (g) (g) (g) (g) (g) (HPLC) 1.0 50% Water 25.05 4.52 516.34 575.33195.26 380.79 12.59 3.617 50% MIBK same as above 1.0 50% Water 25.09 0530.89 573.3 183.95 389.35 14.07 3.726 50% MIBK same as above 6.191 1.050% Water 25.17 4.87 578.18 600.18 325.8 274.38 0.00 50% Cyclohexanonesame as above

Examples 79-84

Further reactions were performed under the same procedure as Example 75.Changes were made to the concentration of sugar, solvent mixture, and anadditional acid catalyst. Also the Parr reactor was purged with nitrogenbefore and after the reaction. The Parr reactor mixing was alsoincreased to 400 rpm. Table 6 outlines the reactions, conditions, andHPLC results.

TABLE 6 Liquid Liquid Hydrolysate Mole/L Mole/L Hydrolysate Recovered +Top Bottom Sugar Sulfuric PTSA Recovered Water Layer Layer ExampleSolution II Solvent Acid (wt %) (g) (g) (g) (g) 5 (top layer) 1.0 50%Water 0.5 1 516.34 575.33 195.26 380.79 50% MIBK 5 (Bottom Layer) sameas above 6 (top layer) 1.0 50% Water 0.5 0 530.89 573.3 183.95 389.3550% MIBK 6 (Bottom Layer) same as above 7 (top layer) 1.0 50% Water 0.51 578.18 600.18 325.8 274.38 50% Cyclohexanone 7 (Bottom Layer) same asabove Dry Solids LA FA Furfury HMF Recovered wt % wt % 1 wt % wt % LA %Example (g) (HPLC) (HPLC) (HPLC) (HPLC) (g) Solids 5 (top layer) 12.593.617 0.874 0 0.05 7.06 2.44 5 (Bottom Layer) same as above 0.00 NA 6(top layer) 14.07 3.726 0.832 0 0.057 6.85 2.65 6 (Bottom Layer) same asabove 6.191 2.802 0 0.05 24.10 NA 7 (top layer) 0.00 0.00 7 (BottomLayer) same as above NA

The solids in Example 79 did not stick to the sides of the reactor orthe stirrer blades, while in Exs. 75-78 the solids were stuck to thesides of the reactor, the bottom of the reactor and the stir shaft. Theywere difficult to remove.

Molar 95% Liquid Reaction Corn Sugar Sulfuric Hydrolysate water DrySolids LA FA Notebook Sweet Solution I Acid Recovered rinse Recovered wt% wt % LA % # Example 90 (g) Solvent (g) (g) (g) (g) (HPLC) (HPLC) (g)Solids SMS163-60 79 1.5 635 100% 25.01 511.72 210.93 27.65 5.794 2.83541.87 5.40 Water with 5% lignin

Referring now to FIGS. 1 a and 1 b. FIG. 1 a provides a general processdescription for one embodiment for the production of levulinic acid.Water, mineral acid and biomass are added to a reactor under reactionconditions to convert the biomass into various products, includinglevulinic acid and formic acid as well as solids char. The solids arethen removed from the reaction mixture. The reaction mixture is thencombined with an extraction solvent, which extracts a majority of thelevulinic acid and formic acid from the water and sulfuric acid. In oneembodiment, the formic acid is removed from the hydrolysate, or reactionmixture, either before or after the solids removal step but prior toadding the extraction solvent for levulinic acid. This can beaccomplished by methods known in the art, such as distillation, steamstripping or extraction. In other embodiments, the formic acid can beextracted out of the reaction mixture after the extraction of levulinicacid utilizing a different extraction solvent than that used forlevulinic acid. In still another embodiment, the formic acid andlevulinic acid are both extracted using the same extraction solvent. Thewater and sulfuric acid is then optionally recycled back to the reactorand the formic acid and levulinic acid are separated from the extractionsolvent, after which the extraction solvent can be recycled back to bere-used in the extraction step.

The reactor can be a batch reactor, a CSTR or a plug reactor. Themineral acid is sulfuric acid (H₂SO₄), hydrochloric acid (HCl),hydrobromic acid (HBr) or hydroiodic acid (HI), preferably sulfuricacid. The biomass comprises sludges from paper manufacturing process;agricultural residues; bagasse pity; bagasse; molasses; aqueous oak woodextracts; rice hull; oats residues; wood sugar slops; fir sawdust;naphtha; corncob furfural residue; cotton balls; raw wood flour; rice;straw; soybean skin; soybean oil residue; corn husks; cotton stems;cottonseed hulls; starch; potatoes; sweet potatoes; lactose; sunflowerseed husks; sugar; corn syrup; hemp; waste paper; wastepaper fibers;sawdust; wood; residue from agriculture or forestry; organic componentsof municipal and industrial wastes; waste plant materials from hard woodor beech bark; fiberboard industry waste water; post-fermentationliquor; furfural still residues; and combinations thereof, a C5 sugar, aC6 sugar, a lignocelluloses, cellulose, starch, a polysaccharide, adisaccharide, a monosaccharide or mixtures thereof. Preferably thebiomass is high fructose corn syrup, a mixture of at least two differentsugars, sucrose, an aqueous mixture comprising fructose, an aqueousmixture comprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof, and more preferably, the biomasscomprises fructose, glucose or a combination thereof

FIG. 1 b provides a more specific process description for one embodimentfor the production of levulinic acid.

Feeds

Concentration of feeds are controlled to maintain desired reactionstoichiometry. “Make-up” stream flows are controlled based on thecomposition and flow rate of the recycle stream.

Reactors

One, optionally two, reactors are used to convert fructose to thedesired products. The reactors are optionally vented to maintain aninternal pressure; the vent stream is optionally collected to recoversteam and formic acid product; the vent stream can all be returned tothe reactor as a reflux. If there are two reactors in series, the firstreactor is optionally controlled at a different temperature and at ahigh concentration of acid in order to achieve desired conversion andselectivity. The first reactor would generally be controlled at a lowertemperature than the second. Optionally, a process step between the tworeactors may be used to separate “tar” solids and/or to preferentiallyextract the reaction products (away from the aqueous feed) to feed intothe second reactor.

The reactors may be operated in a batch-wise (wherein the reactants arefed to the reactor and the reaction continues until the desired degreeof conversion, and the products are then emptied from the reactor) or ina continuous fashion (wherein reactants are fed continuously and theproducts are removed continuously). In one embodiment, the reactors arerun in a continuous fashion with products removed in a steady fashion orthe reactants are removed in a pulsed fashion. In another embodiment,the reactors are run in a batch mode, with the biomass preferably beingadded to the reactor over a period of time t.

The agitation in the reactors should be adequate to preventagglomeration of solid co-products which may be formed during thereaction. Specifically, the reactors should be designed with sufficientaxial flow (from the center of the reactor to the outer diameter andback).

Flash

The reaction products may be optionally cooled in a “flash” process. Theflash step rapidly cools the reaction products by maintaining a pressurelow enough to evaporate a significant fraction of the products. Thispressure may be at or below atmospheric pressure. The evaporated productstream may be refluxed through stages of a distillation column tominimize the loss of desired reaction products, specifically levulinicacid, and to ensure recovery of formic acid reaction products andsolvent. Recovered solvent may be recycled back to reactor 1 or 2.

The “bottoms” or less volatile stream from the flash step is advanced tothe solids separation stage.

Solids Separation

In the solids separation stage of the process, the solvent and desiredreaction products, specifically levulinic acid and formic acid, areseparated from any solids which may have formed during the reactionphase. The solids may be separated through a combination of centrifuge,filtration, and settling steps (ref Perrys Chemical EngineeringHandbook, Solids Separation). The separated solids may be optionallywashed with water and solvents to recover desired reaction products orsolvent which may be entrained in or adsorbed to the solids. It has beenfound that in some embodiments, such as those reactions employing highlevels of mineral acid (greater than 20%) that are reacted at lowertemperatures, such as between 60-110 C, the solids may have densityproperties similar to the liquid hydrolysate which effectively allowsthe solids to be suspended in solution. In these embodiments, certainseparation techniques such as centrifugation are not as effective. Inthese embodiments filtration utilizing filter media having a pore sizeless than about 20 microns has been found to effectively remove solidsfrom the mixture. When removing solids from the system a solid “cake” isformed. It is desirable that the cake be up to 50% solids. Thus anyseparation technique that obtains a cake having a higher amount ofsolids is preferred. A certain amount of LA and mineral acid will bepresent in the cake and it may be desirable to wash the cake with anextraction solvent or water to recover LA.

It has also been surprisingly found that the solid particles in the highmineral acid and lower temperature embodiments are easily filtered anddo not inhibit flow as the cake is formed. It is believed that theproperties of the char formed under these process conditions are suchthat any cake remains porous enough that a small filter size (less than20 microns) can be utilized while maintaining a high flow rate throughthe medium.

Referring now to FIGS. 2 a through 2 e, solid, black char was isolatedfrom a fructose hydrolysate reaction mixture by filtration. The char wasrinsed with water 2 times to recover additional levulinic acid andformic acid, and then, the char was dried at 50-60° C. and 30 Torr forat least 12 h. The dried char was subjected to solvent extractionaccording to FIG. 2 b. A considerable amount of material was extractedfrom the char. Proton NMR was used to analyze the soluble extractfraction, and it was found to contain mostly levulinic acid and formicacid. Thus, this solvent extraction method is surprisingly advantageousfor further recovery of levulinic acid from the reaction mixture.

The isolated solids may be incinerated to generate power or disposed.

The liquid stream, comprising (but not limited to) water, acid, solvent,levulinic acid, formic acid, and some “soluble tars” are advanced to theextraction stage of the process.

Extraction

In the extraction stage of the process, the liquid stream is mixed withan extraction solvent stream. The preferred extraction solvent dissolveslevulinic acid more effectively than the other products in the liquidstream. The preferred solvent does not dissolve significantly into thewater phase. Extraction configurations are preferably multi-stage andcontinuous, as described in Perry's Chemical Engineering Handbook.

The aqueous raffinate is recycled to the reactor phase, after optionaldistillation or purification steps to adjust the relative concentrationsof solvent, water, and acid in the raffinate.

The extract solvent phase contains levulinic acid and formic acid and isprogressed to the solvent removal stage of the process.

Suitable solvents to extract LA include, for example, polarwater-insoluble solvents such as MIBK, MIAK, cyclohexanone, o, m, andpara-cresol, substituted phenols, for example, 2-sec butyl phenol,C4-C18 alcohols, such as n-pentanol, isoamyl alcohol, n-heptanol,2-ethyl hexanol, n-octanol, 1-nonanol, cyclohexanol, methylene chloride,1,2-dibutoxy-ethylene glycol, acetophenone, isophorone,o-methoxy-phenol, methyl-tetrahydrofuran, tri-alkylphosphine oxides(C4-C18) and ortho-dichlorobenzene and mixtures thereof. Such solventsare used generally at room temperature so as not to serve as potentialreaction component.

Solvent Removal

Levulinic acid may be separated from the solvent phase by evaporating ordistilling the solvent. Alternatively, the levulinic acid may becrystallized from the solvent phase in a crystallization process. Thesolvent removal process may be a combination of distillation andcrystallization. The recovered solvent may be recycled to the extractionstep or to the reactor step.

The resulting stream of highly concentrated levulinic acid may beadvanced for further chemical derivatization or may be further purifiedin another distillation step such as high vacuum wipe-film-evaporationor falling film evaporation. Preferably the levulinic acid stream iskept at a low temperature throughout the solvent removal steps toinhibit the formation of angelica lactone.

Mineral Acids

Suitable acids used to convert the biomass materials described herein,including sugars, include mineral acids, such as but not limited, tosulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid,nitric acid, phosphoric acid, boric acid, hydrofluoric acid, perchloricacid and mixtures thereof

Example 80

Into a three neck 250 mL round bottom flask 130.01 g deionized water and23.51 g (0.13 mol, 0.72M) D-fructose were charged. The round bottomflask was equipped with a magnetic stir bar, thermocouple, condenser,and glass stopper. The stir plate was set to stir at a rate of 550 RPMand the fructose quickly dissolved. Once the fructose was dissolved,63.78 g (0.65 mol, 3.60M) sulfuric acid was added into the flask. Theheat was turned on and set to a temperature of 80° C. Samples were takenas the reaction mixture was heated up and analyzed by HPLC. The reactionwas held at 80° C. for four hours and then the reaction was shut down.The solids that were formed during the reaction were filtered and thendried in a vacuum oven overnight.

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Solids 3.44 % Solids based on Fructose 14.63 % Solids based onTotal Reaction Weight 1.58

Grams of LA 8.28 % LA based on Fructose 35.20 % LA based on TotalReaction Weight 3.81

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Example 81

Into a three neck 250 mL round bottom flask 133.12 g deionized water and23.49 g (0.13 mol, 0.71M) D-fructose were charged. The round bottomflask was equipped with a magnetic stir bar, thermocouple, condenser,and glass stopper. The stir plate was set to stir at a rate of 550 RPMand the fructose quickly dissolved. Once the fructose was dissolved,63.75 g (0.65 mol, 3.54M) sulfuric acid was added into the flask. Theheat was turned on and set to a temperature of 90° C. Samples were takenas the reaction mixture heated up and were analyzed by HPLC. Thereaction was held at 90° C. for four hours and then the reaction wasshut down. Samples were taken throughout the entire reaction andanalyzed by HPLC. The solids that were formed during the reaction werefiltered and then dried in a vacuum oven overnight.

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Solids 3.77 % Solids based on Fructose 16.05 % Solids based onTotal Reaction 1.71 Weight

Grams of LA 10.55 % LA based on Fructose 44.90 % LA based on TotalReaction Weight 4.79

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Example 82

Into a three neck 250 mL round bottom flask 130.02 g deionized water and23.42 g (0.13 mol, 0.72M) D-fructose were charged. The round bottomflask was equipped with a magnetic stir bar, thermocouple, condenser,and glass stopper. The stir plate was set to stir at a rate of 550 RPMand the fructose quickly dissolved. Once the fructose was dissolved,63.78 g (0.65 mol, 3.60M) sulfuric acid was added into the flask. Theheat was turned on and set to a temperature of 90° C. The reaction washeld at 90° C. for two hours and twenty minutes and then the reactionwas shut down.

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Solids 5.19 % Solids based on Fructose 22.16 % Solids based onTotal Reaction Weight 2.39

Grams of LA 8.25 % LA based on Fructose 35.22 % LA based on TotalReaction Weight 3.80

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Example 83

Into a three neck 250 mL round bottom flask 65.04 g deionized water and11.71 g (0.065 mol, 0.60M) D-fructose were charged. The round bottomflask was equipped with a magnetic stir bar, thermocouple, condenser,and glass stopper. The stir plate was set to stir at a rate of 550 RPMand the fructose quickly dissolved. Once the fructose was dissolved,63.80 g (0.65 mol, 6.04M) sulfuric acid was added into the flask slowly.Once all of the sulfuric acid was added to the reaction mixture the heatwas turned on and set to a temperature of 80° C. The reaction was heldat 80° C. for two hours and then the reaction was shut down. The solidsthat were formed during the reaction were filtered and then dried in avacuum oven overnight.

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Solids 2.90 % Solids based on Fructose 24.77 % Solids based onTotal Reaction Weight 2.06

Grams of LA 5.84 % LA based on Fructose 49.84 % LA based on TotalReaction Weight 4.15

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Example 84

Into a three neck 250 mL round bottom flask 60.06 g deionized water and10.88 g (0.06 mol, 0.61M) D-fructose were charged. The round bottomflask was equipped with a magnetic stir bar, thermocouple, condenser,and glass stopper. The stir plate was set to stir at a rate of 550 RPMand the fructose quickly dissolved. Once the fructose was dissolved, anice water bath was placed beneath the round bottom flask in order tocool the reaction mixture. The ice water bath was used to prevent thereaction mixture from getting too hot when the sulfuric acid was added.Once the reaction mixture was cold, 58.96 g (0.60 mol, 6.04M) sulfuricacid was added into the flask making sure to keep the reaction mixturebelow 45° C. Once all of the sulfuric acid was added to the reactionmixture the ice water bath was removed and the heating mantle wassituated under the flask. The heat was turned on and set to atemperature of 90° C. The reaction was held at 90° C. for thirty minutesand then the reaction was shut down, the heating mantle was removed andan ice water bath was used to cool the mixture. The solids that wereformed during the reaction were filtered and then dried in a vacuum ovenovernight.

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Solids 5.49 % Solids based on Fructose 50.46 % Solids based onTotal Reaction Weight 4.23

Grams of LA 4.08 % LA based on Fructose 37.51 % LA based on TotalReaction Weight 3.14

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Example 85

Into a three neck 250 mL round bottom flask 60.04 g deionized water and10.91 g (0.06 mol, 0.46M) D-fructose were charged. The round bottomflask was equipped with a magnetic stir bar, thermocouple, condenser,and glass stopper. The stir plate was set to stir at a rate of 550 RPMand the fructose quickly dissolved. Once the fructose was dissolved, anice water bath was placed beneath the round bottom flask in order tocool the reaction mixture. The ice water bath was used to prevent thereaction mixture from getting too hot when the sulfuric acid was added.Once the reaction mixture was cold, 117.73 g (1.2 mol, 9.13M) sulfuricacid was added into the flask making sure to keep the reaction mixturebelow 30° C. Once all of the sulfuric acid was added to the reactionmixture the ice water bath was removed and a heating mantle was situatedunder the flask. The heat was turned on and set to a temperature of 50°C. The reaction was held at 50° C. for thirty minutes and then thereaction was shut down, the heating mantle was removed and cooled withthe ice water bath. Once the reaction mixture was cooled it was filteredin order to obtain any solids that were formed, the surprising thing wasthat no solids were observed. The reaction mixture was placed back intothe round bottom flask and set up again in order to continue thereaction. The heat was turned on and set back to 50° C. The reaction wasleft to run for another 433 minutes and then was shut down. The reactionmixture was filtered again and this time solids were observed. Thesolids were put into a vacuum oven to dry overnight.

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Solids 8.68 % Solids based on Fructose 79.56 % Solids based onTotal Reaction Weight 4.60

Grams of LA 3.85 % LA based on Fructose 35.31 % LA based on TotalReaction Weight 2.04

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Example 86

Into a three neck 250 mL round bottom flask 40.04 g deionized water and7.21 g (0.04 mol, 0.37M) D-fructose were charged. The round bottom flaskwas equipped with a magnetic stir bar, thermocouple, condenser, andglass stopper. The stir plate was set to stir at a rate of 550 RPM andthe fructose quickly dissolved. Once the fructose was dissolved, an icewater bath was placed beneath the round bottom flask in order to coolthe reaction mixture. The ice water bath was used to prevent thereaction mixture from getting too hot when the sulfuric acid was added.Once the reaction mixture was cold, 117.78 g (1.2 mol, 11.02M) sulfuricacid was added into the flask making sure to keep the reaction mixturebelow 30° C. Once all of the sulfuric acid was added to the reactionmixture the ice water bath was removed and a heating mantle was situatedunder the flask. The heat was turned on and set to a temperature of 50°C. The reaction was held at 50° C. for forty five minutes and then thereaction was shut down, the heating mantle was removed and cooled withthe ice water bath. In order to form more product, levulinic acid andformic acid, the reaction mixture was heated back up to 50° C. and leftto react for another thirty minutes. After the thirty minutes thereaction was shut down and cooled with an ice water bath. The reactionmixture was filtered but no solids were observed.

Grams of LA 2.43 % LA based on Fructose 33.65 % LA based on TotalReaction Weight 1.47

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Example 87

Into a three neck 250 mL round bottom flask 40.07 g deionized water and7.35 g (0.04 mol, 0.37M) D-fructose were charged. The round bottom flaskwas equipped with a magnetic stir bar, thermocouple, condenser, andglass stopper. The stir plate was set to stir at a rate of 550 RPM andthe fructose quickly dissolved. Once the fructose was dissolved, an icewater bath was placed beneath the round bottom flask in order to coolthe reaction mixture. The ice water bath was used to prevent thereaction mixture from getting too hot when the sulfuric acid was added.Once the reaction mixture was cold, 117.76 g (1.2 mol, 11.00M) sulfuricacid was added into the flask making sure to keep the reaction mixturebelow 30° C. Once all of the sulfuric acid was added to the reactionmixture the ice water bath was removed and a heating mantle was situatedunder the flask. The heat was turned on and set to a temperature of 50°C. The reaction was held at 50° C. for two hours and then the reactionwas shut down, the heating mantle was removed and cooled with the icewater bath. The reaction mixture was filtered and the solids were placedinto a vacuum oven to dry.

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Solids 3.00 % Solids based on Fructose 40.82 % Solids based onTotal Reaction Weight 1.82

Grams of LA 2.55 % LA based on Fructose 34.64 % LA based on TotalReaction Weight 1.54

It was observed that reduced char was present at filtration as comparedto reactions at higher temperatures and lower acid levels and little tono char was accumulated on the reactor components.

Examples 80-87 demonstrate that running the reactions at reducedtemperatures (less than 100 C) improves the selectivity for levulinicacid, and increased levels of mineral acid (such as 40-72% of sulfuricacid) lead to faster reaction times. Combining these 2 features resultsin faster reactions that are highly selective to levulinic acid withsignificantly less char.

Reactor Modeling

A combination of experimental and modeling research has been conductedin order to analyze and recommend continuous reactor designs for theproduction of levulinic acid from fructose. The main focus of thisexample is a description of kinetic and reactor modeling methods, modelvalidation, and recommended reactor configurations that maximize theyield of the desired product while minimizing undesirable byproducts,such as HMF and char.

A validated kinetic model has been developed by adapting anacid-catalyzed glucose decomposition mechanism from the thesis ofGirsuta to describe batch reactor data for the conversion of fructose tolevulinic acid. Kinetic parameters in the model were adjusted usingregression analysis to fit the model to the data. The model has beenimplemented for two types of ideal continuous reactors: a continuousstirred tank reactor (CSTR) and a plug flow reactor (PFR). The CSTRmodel predictions compared favorably with a single data set from acontinuous flow reactor experiment. The experimental and modelingresults illustrate that byproduct formation is minimized using highercatalyst (H₂SO₄) concentrations (e.g. 5 mole/liter) and lowertemperatures (50 to 100° C.) than employed in the thesis.

The validated model was implemented in an Aspen Plus flowsheet to studythe effect of multiple reactor configurations, residence times andreactor temperatures on the yields of the desired product (levulinicacid) and the undesired byproduct (humins, or char). More than fiftyconfigurations were run and the resulting yield and conversionpredictions were analyzed to recommend a reactor configuration forexperimental study. The cases studied all used a feed with catalyst(H₂SO₄) concentration of 5 mole/liter and fructose concentration of 1mole/liter.

Examples 88-102 Model Predictions for Multiple Reactor Configurations

The reaction rate mechanism that was implemented and verified in Aspenfor fructose decomposition was used to study the performance of networksof CSTR and PFR reactors. Several networks were studied at the same timeto simplify comparison of performance. The Aspen flowsheet diagram isshown in FIG. 3. Five configurations were studied, as described in thefigure.

Case A: Two CSTR reactors in series: large, then small

Case B: A small PFR followed by a large CSTR

Case C: A single CSTR

Case D: A large CSTR followed by a small PFR

Case E: Three CSTR reactors in series

The flowsheet simulation was run many times using an acid concentrationof 5 mole/liter and a sugar concentration of 1 mole/liter. The totalresidence time was constrained to be 180 minutes for all cases, toprovide a consistent basis for comparison. The temperature rangedescribed in this report ranged from 100 to 120° C. Other simulationswere done at temperatures ranging from 90 to 100° C., but they had lowerconversion and are not described in this report. The individualresidence times for the reactors and the reactor temperatures werevaried for the study.

The results from three interesting sets of cases are shown in Table 7.Examples 88-102 are described in Table 7. In set 1, all temperatureswere set to 100° C., and the reactor residence times were at their basevalue. In set 2, temperatures were also 100° C., but the residence timefor the first reactor in each sequence was increased. This modificationreduced the yield to the undesirable humin product. In set 3, thetemperature for the second (or third) reactor was increased. In case 3D,the CSTR residence time was also increased. This modification increasedthe yield of desirable levulinic acid but did not significantly changethe yield to the undesirable humins product. Cases 3D and 3E have verysimilar performance predictions.

Configurations 3D and 3E both had a large CSTR reactor followed by oneor two small reactors at higher temperature. In case 3D, the secondreactor is a PFR, while in case 3E, the second and third reactors aresmall CSTRs. These configurations both had fructose conversion greaterthan 99%, soluble Levulinic Acid yield above 63%, Humins yield of 1.23%,and HMF yield below 0.1%. Total yield of Levulinic Acid (soluble &insoluble) was predicted to be greater than 94% for theseconfigurations.

TABLE 7 Results summary for Sets 1-3 (Examples 88-102). Ex. 88 Ex. 89Ex. 90 Ex. 91 Ex. 92 Ex. 93 Ex. 94 Ex. 95 Description Case 1A Case 1BCase 1C Case 1D Case 1E Case 2A Case 2B Case 2C yield LA 60.07 61.4755.08 62.70 61.56 59.19 60.33 55.08 Soluble fructose 95.88 99.30 89.4998.95 98.07 94.75 97.81 89.49 conversion Yield 1.23 1.84 1.05 1.31 1.401.14 1.75 1.05 Humins Ratio LA/ 49.00 33.43 52.42 47.73 43.94 52.0034.45 52.42 humins Yield Lev. A 89.67 91.77 82.22 93.52 91.86 88.3590.02 82.22 Total Yield 1.40 0.18 3.15 0.26 0.61 1.84 0.88 3.15 of HMFRes. Time 120 180 120 60 150 180 CSTR 1 Res. Time 60 120 60 30 150 CSTR2 Res. Time 60 CSTR 3 Res. Time 61.84 61.89 31 PFR Total Res. 180 182180 182 180 180 181 180 Time (min) Temp 100 100 100 100 100 100 CSTR 1Temp 100 100 100 100 100 CSTR 2 Temp 100 CSTR 3 Temp PFR 100 100 100 Ex.96 Ex. 97 Ex. 98 Ex. 99 Ex. 100 Ex. 101 Ex. 102 Description Case 2D Case2E Case 3A Case 3B Case 3C Case 3D Case 3E yield LA 61.03 61.21 62.9662.26 55.08 63.57 63.49 Soluble fructose 96.94 97.20 99.04 99.74 89.4999.82 99.74 conversion Yield 1.23 1.23 1.14 1.66 1.05 1.23 1.23 HuminsRatio LA/ 49.79 49.93 55.31 37.42 52.42 51.86 51.79 humins Yield Lev. A91.07 91.33 93.96 92.91 82.22 94.83 94.75 Total Yield 1.05 0.96 0.440.09 3.15 0.09 0.09 of HMF Res. Time 150 120 150 180 170 120 CSTR 1 Res.Time 30 30 150 30 CSTR 2 Res. Time 30 30 CSTR 3 Res. Time 31 30 10 PFRTotal Res. 181 180 180 180 180 180 180 Time (min) Temp 100 100 100 100100 100 CSTR 1 Temp 100 120 120 110 CSTR 2 Temp 100 120 CSTR 3 Temp PFR100 100 120

Examples with Continuous Feed Aspects or Simple Batch Processes

HLPC Method

The instrument used was a WATERS 2695 LC system with a WATERS 2998 PDAdetector. A Hamilton PRP-X300 column (7 μm 250×4.1 mm) was used with 5μL injections. The column temperature was maintained at 50° C. There aretwo mobile phases used. “Solvent A” is 20 mM of Phosphoric Acid in DIH₂O. “Solvent B” is Methanol (HPLC Grade). An isocratic flow of 2 mL/minis used with a (80% Solvent A/20% Solvent B) mobile phase mixture.Sample data is analyzed by extracting a chromatogram at 210 nmwavelength.

LC-RI method The instrument used was a WATERS 1515 LC pump with a WATERS717 autosampler and WATERS 2410 RI detector. A Supelcosil-LC-NH2 (250mm×4.6 mm×5 μm) was used with 10 μL injections. The column temperaturewas maintained at 50° C. The mobile phase was 75% Acetonitrile/25%Nanopure H2O. An isocratic flow of 1 mL/min was used. Samples werefiltered and diluted 5-10× with Nanopure H2O before analysis.

Example 103

122.01 g deionized water and 108.03 g (96-98%) sulfuric acid was chargedinto a 500 mL 4-neck round bottom flask. 40.08 g HFCS 55 (high fructosecorn syrup; ADM, Inc. 55% Fructose) was charged into a 60 mL syringe.The round bottom flask was situated in a heating mantle and equippedwith a magnetic stir bar, thermocouple, condenser, glass stopper and thesyringe pump inlet tube. The water and sulfuric acid solution wasstirred at 650 RPM and heated up to a temperature of 90° C. The HFCS 55was added using a syringe pump over a course of two hours at a rate of15 mL/hr. After all of the HFCS 55 had been added into the round bottomflask, the reaction was held at temperature for one hour. After a totalreaction time of three hours a sample was taken to be analyzed by LC-UVand LC-RI and then the reaction was shut down and allowed to cool toambient temperature. Once the reaction mixture was cool, the solids werefiltered out and then washed with water and acetone. The solids werethen measured using a moisture analyzer.

% % % % % g g g g g g FA LA HMF Fructose Glucose FA LA HMF FructoseGlucose Char 1.45 3.19 0.01 0.00 2.79 3.58 7.88 0.02 0.00 6.89 2.49

Example 104

30 g Fructose, 37.02 g Glucose was dissolved into 33.09 g deionizedwater. Then 40.02 g of the sugar solution was placed into a 60 mLsyringe. 122.02 g deionized water and 108.11 g sulfuric acid (96-98%)was charged into a 500 mL 4-neck round bottom flask. The round bottomflask was situated in a heating mantle and equipped with a magnetic stirbar, thermocouple, condenser, glass stopper and the syringe pump tubeinlet. The water and sulfuric acid solution was stirred at 650 RPM andheated up to a temperature of 90° C. The sugar solution was added usinga syringe pump over a course of two hours at a rate of 15 mL/hr. Afterall of the sugar solution had been added into the round bottom flask,the reaction was held at temperature for one hour. After a totalreaction time of three hours a sample was taken and analyzed by LC-UVand LC-RI and then the reaction was shut down and allowed to cool toambient temperature. Once the reaction mixture was cool, the solids werefiltered out and then washed with water and acetone. The solids werethen measured using a moisture analyzer.

% % % % % g g g g g g FA LA HMF Fructose Glucose FA LA HMF FructoseGlucose Char 1.17 2.82 0.00 0.00 4.77 2.89 6.97 0.00 0.00 11.78 1.211

Examples 105, 106 and 107

15 mL of the resulting solution from Example 1 was added to an empty 3oz. high pressure, high temperature reaction vessel equipped with athermocouple and pressure gauge for monitoring the internal temperatureand pressure (Example 4a). A second reaction vessel was also chargedwith 15 mL of the resulting solution from Example 2 (Example 4b). Afterproper assembly, the reaction vessels were then placed into a 140 C hotoil bath to reach an internal temperature of around 130 C. After 2 hoursthe reaction vessels were removed from the hot oil and placed in a roomtemperature water bath for 1 minute to begin cooling. Following the roomtemperature water bath, the reactors were placed in an ice water bath toquench the reactions. Once the reactions had cooled completely, thereactor vessels were opened and the mixtures were analyzed individuallyby HPLC. Any solids formed during the reaction were also washed with DIwater and weighed. The solids water wash was also analyzed by HPLC andincluded in the final product calculations.

The HPLC results for Example 105 show the glucose completely convertedto products. The levulinic acid to solids mass ratio was 1.8. (Weight ofLA to weight to solids.) For Example 106 the HPLC results show theglucose reacting to about 88% conversion. The levulinic acid to solidsmass ratio was 1.74.

A third 3 oz. high pressure, high temperature reaction vessel equippedwith a thermocouple and pressure gauge for monitoring the internaltemperature and pressure was charged with 15 mL of the resultingsolution from Example 104 (Example 107). After proper assembly, thereaction vessel was placed into a 120 C hot oil bath to reach aninternal temperature of around 110 C. After 3 hours the reaction vesselwas removed from the hot oil and placed in a room temperature water bathfor 1 minute to begin cooling. Following the room temperature waterbath, the reactor was placed in an ice water bath to quench thereaction. Once the reaction had cooled completely, the reactor vesselwas opened and the mixture was analyzed by HPLC. Any solids formedduring the reaction were also washed with DI water and weighed. Thesolids water wash was also analyzed by HPLC and included in the finalproduct calculations.

The HPLC results for Example 107 show the glucose conversion to be 87%.The levulinic acid to solids mass ratio was 2.32.

Example 108

47.95 g deionized water and 99.68 g sulfuric acid (96-98%) were chargedinto a 250 mL 3-neck round bottom flask. 2.40 g Fructose and 10.02 gdeionized water was charged into a small beaker and placed on a stirplate to dissolve the fructose. The round bottom flask was situated in aheating mantle and equipped with a magnetic stir bar, thermocouple,condenser and glass stopper. The water and sulfuric acid was stirred ata rate of 650 RPM and heated up to a temperature of 90° C. The fructosesolution was injected all at once into the reaction mixture and allowedto react for one hour. After a reaction time of one hour a sample waspulled to be analyzed by LC-UV and LC-RI then the reaction was shutdown. Once the reaction mixture was at ambient temperature it wasfiltered and no solids were observed.

% % % % g g g g g FA LA HMF Fructose FA LA HMF Fructose Char 0.29 0.640.00 0.00 0.46 1.02 0.00 0.00 0.00

Example 109

84.04 g deionized water and 63.79 g sulfuric acid (96-98%) was chargedinto a 250 mL 3-neck round bottom flask. 1.7108 g HMF and 10.02 gdeionized water was charged into a scintillation vial and placed on astir plate to dissolve the HMF. The round bottom flask was situated in aheating mantle and equipped with a magnetic stir bar, thermocouple,condenser and glass stopper. The water and sulfuric acid mixture wasstirred at 650 RPM and heated up to a temperature of 90° C. The HMFsolution was then injected all at once into the round bottom flask andallowed to react for one hour. The reaction was shut down after areaction time of one hour and a sample was taken at the end and analyzedby LC-UV. Once the reaction mixture was at ambient temperature it wasfiltered and no solids were observed.

% FA % LA % HMF g FA g LA g HMF g Char 0.44 0.97 0.00 0.70 1.55 0.000.00

Example 110

1.6658 g HMF and 10.0437 g deionized water was charged into ascintillation vial and set on a stir plate to dissolve the HMF. 77.06 gdeionized water and 76.55 g sulfuric acid (96-98%) was charged into a250 mL 3-neck round bottom flask. The round bottom flask was situated ina heating mantle and equipped with a magnetic stir bar, thermocouple,condenser, and glass stopper. The water and sulfuric acid was heated upto 90° C. while stirring at 650 RPM. Once the HMF was all dissolved itwas injected all at once into the water and sulfuric acid mixture. Thereaction was shut down after a reaction time of 30 minutes and a samplewas taken at the end and analyzed by LC-UV. Once the reaction mixturewas at ambient temperature it was filtered and no solids were observed.

% FA % LA % HMF g FA g LA g HMF g Char 0.40 0.99 0.00 0.65 1.62 0.000.00

Example 111

3.785 g Fructose, 2.657 g HMF and 10.014 g deionized water was chargedinto a beaker then placed on a stir plate to dissolve the fructose andHMF. 139.35 g deionized water and 103.03 g sulfuric acid (96-98%) wascharged into a 500 mL 4-neck round bottom flask. The round bottom flaskwas situated in heating mantle and equipped with a magnetic stir bar,thermocouple, condenser, and two glass stoppers. The water and sulfuricacid were stirred at 650 RPM and heated to 90° C. The fructose and HMFsolution was then injected into the round bottom flask all at once andallowed to react for one hour. After a reaction time of one hour asample was taken to be analyzed by LC-UV and LC-RI and then shut down.Once the reaction mixture was at ambient temperature it was filtered andno solids were observed.

% % % % g g g g g FA LA HMF Fructose FA LA HMF Fructose Char 0.45 1.110.23 0.279 1.05 2.59 0.54 0.65 0.00

Example 112

13.24 g HMF and 30.05 g deionized water was charged into a beaker thenplaced the beaker on a stir plate to dissolve the HMF. 113.35 gdeionized water and 103.05 g (96-98%) sulfuric acid was charged into a500 mL 4-neck round bottom flask. The round bottom flask was situated ina heating mantle and equipped with a magnetic stir bar, thermocouple,condenser, glass stopper and the syringe pump inlet. The water andsulfuric acid was stirred at 650 RPM and heated to a temperature of 90°C. The HMF solution was added using a syringe pump over a course of fivehours at a rate of 7.4 mL/hr. After all of the HMF had been added intothe round bottom flask, the reaction was held at temperature for onehour. After a total reaction time of six hours a sample was taken andanalyzed by LC-UV and then the reaction was shut down and allowed tocool to ambient temperature. Once the reaction mixture was cool, thesolids were filtered out and then washed with water and methylenechloride and then the char was left to dry overnight. The char was thenput into a scintillation vial which was then placed in a vacuum oven todry until a constant weight was obtained.

% FA % LA % HMF g FA g LA g HMF g Char 2.21 4.71 0.00 5.37 11.44 0.000.745

Example 113

A 250 mL Erlenmeyer flask was charged with 114.95 g of 64% SulfuricAcid, and 64.27 g de-ionized water. The acidic water mixture was placedin an ice bath and allowed to cool. After the solution was cool, 3.78 gFructose and 2.65 g Hydroxymethylfurfural (HMF) were also added to theErlenmeyer flask. The mixture was mixed well until completely dissolved.The resulting molarities calculate to 0.14M Fructose, 0.14M HMF and 5MSulfuric acid.

15 mL of the prepared solution was added to an empty 3 oz. highpressure, high temperature reaction vessel equipped with a thermocoupleand pressure gauge for monitoring the internal temperature and pressure.After proper assembly, the reaction vessel was then placed into a 100 Chot oil bath to reach an internal temperature of around 90 C. After 60min the reaction vessel was removed from the hot oil and placed in aroom temperature water bath for 1 minute to begin cooling. Following theroom temperature water bath, the reactor was placed in an ice water bathto quench the reaction. Once the reaction had cooled completely, thereactor vessel was opened and the mixture was analyzed by HPLC. Anysolids formed during the reaction were washed with DI water and weighed.The solids water wash was also analyzed by HPLC and included in thefinal product calculations.

The HPLC results for Example 113 show the HMF conversion equal to 99%conversion and the fructose completely reacting away after 60 min. Themolar percent yield of levulinic acid (LA) was 96%. Also the LA tosolids mass ratio was 2.95.

Example 114

A 250 mL Erlenmeyer flask was charged with 114.94 g of 64% SulfuricAcid, and 63.14 g de-ionized water. The acidic water mixture was placedin an ice bath and allowed to cool. After the solution was cool, 3.79 gFructose and 3.98 g Hydroxymethylfurfural (HMF) were also added to theErlenmeyer flask. The mixture was mixed well until completely dissolved.The resulting molarities calculate to 0.14M Fructose, 0.21M HMF and 5MSulfuric acid.

15 mL of the prepared solution was added to an empty 3 oz. highpressure, high temperature reaction vessel equipped with a thermocoupleand pressure gauge for monitoring the internal temperature and pressure.After proper assembly, the reaction vessel was then placed into a 100 Chot oil bath to reach an internal temperature of around 90 C. After 60min, the reaction vessel was removed from the hot oil and placed in aroom temperature water bath for 1 minute to begin cooling. Following theroom temperature water bath, the reactor was placed in an ice water bathto quench the reaction. Once the reaction had cooled completely, thereactor vessel was opened and the mixtures were analyzed individually byHPLC. Any solids formed during the reaction were also washed with DIwater and weighed. The solids water wash was also analyzed by HPLC andincluded in the final product calculations.

The HPLC results for Example 114 show the HMF reacting to 99% conversionand the fructose completely reacting away after 60 min. The molarpercent yield of levulinic acid (LA) was 96.71%. Also the LA to solidsmass ratio was 3.95.

Examples with Continuous Feed and/or Recycling Aspects Example 115Synthesis of LA+FA with a Mixed Sugar Solution by Continuous Feeding

To a 3 neck, 1 L round bottom flask equipped with condenser andthermocouple magnetic stirring was charged 126.45 g H₂O and 311.88 g of64% (wt) H2SO4. The reaction mixture was heated to 90° C. at which point40.5 g of a sugar solution containing 69.3% fructose, 23% water, 6.16%glucose, and 1.54% others was injected over a 5 hour period using asyringe pump. When all of the sugar solution had been added, thereaction mixture was cooled to room temperature and transferred to a 1 LHastelloy C Parr reactor kettle. The reactor was sealed and heated to120° C. for 90 minutes to fully convert any remaining reactant orintermediates to products. During this final step, the pressure of thereactor remained below 25 psi.

TABLE 8 HPLC analytical results of hydrolysis samples taken at varioustimes during the reaction Time of reaction Temperature % Formic %Levulinic (min) (° C.) Acid Acid % HMF 305 89.4 1.539 3.222 0.072 90 1201.526 3.391 Non- Detectable

The above reaction mixture was cooled to room temperature using an icebath. 435 gm of this mixture was poured into a 150 ml Buchner funnelwith a glass frit (4-5 micron filter size), that was placed on top of1000 mL filter flask connected to a Teflon vacuum pump. Vacuum was usedto aid the filtration (<250 mm), filtrate was allowed to drain for 5-10minutes before the Teflon vacuum pump was turned off. 413 gm of filtrateand 22.11 gm of wet solids were obtained (9 for composition details forthe filtrate). The solid was washed with 4×50 mL DI water. Another 10 mLwas added and the filtrate of the 10 mL wash was tested using a pH probe(pH=2.04). The solids were washed with 48 gm of acetone and air driedovernight to give 5.0 gm of dry char (1.04 wt % based on total initialcharge). The char was powdery in nature, and was not sticky. It flowedeasily before filtration, and it did not stick to reactor components.

The 413 gm filtrate was poured into a 1000 mL cell culture spinnerflask, followed by addition of 828 gm of methyl isobutyl ketone (99.8%,Macron chemicals, Philipsburg, N.J.). The solution was stirred at 150rpm for 30 minutes and the two layers were poured into a 2000 mLcylindrical reparatory funnel. The two layers were allowed to phaseseparate over 30 mins. The bottom layer was drained into a 1000 mL threeneck round bottom flask and the top layer (OEX) to a 2000 mL two neckround bottom flask (see Table 9 for composition details for each layer).

The 2000 mL two neck round bottom flask containing the organic extract(OEX) was setup for short path distillation using a magnetic stirrer andheating mantle connected to a variable transformer. The short pathdistillation head was connected to a Teflon vacuum pump and a chiller(set at 10° C.). Temperature of the organic extract and the distillatevapor was measured using a J-type thermocouple. The vacuum wascontrolled to 50 mm using a digivac vacuum controller. The 2000 mL flaskwas subjected to 50 mm vacuum before the heating mantle was turned. Oncethe temperature in the round bottom flask reached 37° C. the methylisobutyl ketone started distilling over (distillate vapor temperature˜37° C.). Distillation was stopped when 80% of the methyl isobutylketone was distilled. The levulinic acid in the bottom of the reactorvessel was isolated as a crude solution in methyl isobutyl ketone (SeeTable 9 for details).

The 1000 mL three neck round bottom flask containing the bottom layer ofthe extraction (raffinate) mixture was also setup for distillation.Setup for distillation included a distillation adapter, condenserconnected to a chiller, J-type thermocouple for the round bottom flaskand distillate vapor, Teflon vacuum pump and an oil bath with ahotplate/stirrer for heating. The pressure was controlled using a J-Kemscientific vacuum controller. The round bottom flask containing theraffinate was subjected to 50 mm vacuum before it was heated. Once thetemperature in the round bottom flask reached 40° C. the water methyliso butyl ketone azeotrope started distilling over. Distillation wascontinued till all the methyl isobutyl ketone was distilled over(distillation receiver shows only increase in water layer, top layerremains constant). The raffinate, after distillation, was used to makethe next batch. (See Table 9 for composition details.

TABLE 9 Composition for filtration, extraction and distillation streams% Levulinic % Formic % Sulfuric Sample stream Mass acid acid acidFiltrate 413 3.39 1.53 Not determined Raffinate, 401 1.31 0.38 39.65before distillation Raffinate, after 355.3 1.57 0.33 44.23 distillationOrganic 827 0.84 0.43 0.12 extract Final crude 142.8 3.58 0.69 0.85product

Example 116 Synthesis of LA and FA with Recycled Raffinate from Example1

To a 3 neck flask equipped with magnetic stirring, a chilled condenser,and thermocouple was charged 348 g of the recycled raffinate fromExample 115. This raffinate contained approximately 157 g H₂SO₄, 5.6 glevulinic acid, and 1.2 g formic acid. To the raffinate charge was added67 g of fresh water to bring the acid concentration in the aqueous phaseto approximately 40%. The aqueous phase was heated to 90° C. before theaddition of 40.35 g of a sugar solution of identical composition to thatused in Example 115 was added over 5 hours. After the sugar addition wascomplete, a 120° C. post cook identical to that of Example 115 was usedto fully convert any unreacted reagents.

TABLE 10 HPLC analytical results of composition. Temperature % Formic %Levulinic Time (min) (° C.) Acid Acid % HMF 305 90 1.876 4.362 0.073 90120 1.958 4.386 Non- Detectable

The above reaction mixture was cooled to room temperature using an icebath. 398.8 gm of this mixture was poured into a 150 ml Buchner funnelwith a glass frit (4-5 micron filter size), that was placed on top of1000 mL filter flask connected to a Teflon vacuum pump. The solidsflowed easily out of the reactor and were not sticky in nature. Vacuumwas used to aid the filtration (<250 mm), filtrate was allowed to drainfor 5-10 minutes before the Teflon vacuum pump was turned off 379.2 gmof filtrate and 19.6 gm of wet solids were obtained. The solid waswashed with 10×100 mL DI water. Another 80 mL was added and the filtrateof the 80 mL wash was tested using a pH probe (pH=1.96). The solids werewashed with 68 gm of acetone and air dried overnight to give 5.43 gm ofdry char (1.21 wt % based on total initial charge)

The extraction and purification procedure was repeated as described inExample 115 to afford a second recycled raffinate stream, RecycledRaffinate Stream from Example 116.

Example 117 Synthesis of LA and FA with Recycled Raffinate Stream fromExample 116

To a 3 neck flask equipped with magnetic stirring, a chilled condenser,and thermocouple was charged 250 g of the recycled raffinate fromExample 116. This raffinate contained approximately 126 g H₂SO₄, 4.2 glevulinic acid, and 1.9 g formic acid. To the raffinate charge wereadded 82 g of 64% fresh H2SO4 and 106 g of fresh water to bring the acidconcentration in the aqueous phase to approximately 40%. The aqueousphase was heated to 90° C. before the addition of 40.85 g of a sugarsolution of identical composition to that used in Example 115 was addedover 5 hours. After the sugar addition was complete, a 120° C. post cookidentical to that of Example 115 was used to fully convert any unreactedreagents. Again, analyses of the hydrolysis mixture at various times arepresented in Table

TABLE 11 HPLC analytical results of composition. Temperature % Formic %Levulinic Time (min) (° C.) Acid Acid % HMF 300 89.8 1.778 4.092 0.07990 120 1.716 4.080 Non- Detectable

The above reaction mixture was cooled to room temperature using an icebath. 447 gm of this mixture was poured into a 150 ml Buchner funnelwith a glass frit (4-5 micron filter size), that was placed on top of1000 mL filter flask connected to a Teflon vacuum pump. The solid charwas not sticky and did not adhere to reactor components. It flowedeasily in the liquid mixture. Vacuum was used to aid the filtration(<250 mm), filtrate was allowed to drain for 5-10 minutes before theTeflon vacuum pump was turned off. 426.1 gm of filtrate and 20.95 gm ofwet solids were obtained. The solid was washed with 9×100 mL DI water.Another 80 mL was added and the filtrate of the 80 mL wash was testedusing a pH probe (pH=2.33). The solids were washed with 68 gm of acetoneand air dried overnight to give 5.0 gm of dry char (1.04 wt % based ontotal initial charge)

The extraction and purification procedure was repeated as described inExample 115 to afford a third recycled raffinate stream, RecycledRaffinate Stream from Example 117.

Example 118 Synthesis of LA and FA with Recycled Raffinate Stream fromExample 117

To a 3 neck flask equipped with magnetic stirring, a chilled condenser,and thermocouple was charged 371 g of the recycled raffinate fromExample 117. This raffinate contained approximately 177.5 g H₂SO₄, 7.1 glevulinic acid, and 2.9 g formic acid. To the raffinate were added 27 gof fresh water and 40.42 g of 64% H₂SO₄ to bring the acid concentrationin the aqueous phase to approximately 40%. The aqueous phase was heatedto 90° C. before the addition of 42.7 g of a sugar solution of identicalcomposition to that used in Example 115 was added over 5 hours. Afterthe sugar addition was complete, a 120° C. post cook identical to thatof Example 1 was used to fully convert any unreacted reagents. Again,analyses of the hydrolysis mixture at various times are presented inTable 12.

TABLE 12 HPLC analytical results of composition. Temperature % Formic %Levulinic Time (min) (° C.) Acid Acid % HMF 305 90.1 2.174 4.626 0.08590 120 2.124 4.380 Non- Detectable

The above reaction mixture was cooled to room temperature using an icebath. 431 gm of this mixture was poured into a 150 ml Buchner funnelwith a glass frit (4-5 micron filter size), that was placed on top of1000 mL filter flask connected to a Teflon vacuum pump. The solid charwas not sticky and did not adhere to reactor components. It flowedreadily in the liquid mixture. Vacuum was used to aid the filtration(<250 mm), filtrate was allowed to drain for 5-10 minutes before theTeflon vacuum pump was turned off. 402.8 gm of filtrate and 28.3 gm ofwet solids were obtained. The solid was washed with 9×100 mL DI water.Another 50 mL was added and the filtrate of the 80 mL wash was testedusing a pH probe (pH=3.3). The solids were washed with 68 gm of acetoneand air dried overnight to give 5.43 gm of dry char (1.13 wt % based ontotal initial charge)

Example 119 Synthesis of LA and FA from Sugar Solution with HigherGlucose Content

To a 3 neck flask equipped with magnetic stirring, a chilled condenser,and thermocouple was charged 200.14 g of 64% H₂SO₄ and 122.53 g freshwater. The aqueous phase was heated to 90° C. before 41.60 g of a sugarsolution containing 64.6% fructose, 24.0% water, 9.9% glucose, and 1.5%others was added over 5 hours. After the sugar addition was complete,the reaction was cooled to room temperature and filtered through a fineglass fitted glass filter to remove approximately 2 wt % insolublehumins that were not sticky in nature. The solids flowed quite easily inthe reactor and did not stick to reactor components.

TABLE 13 HPLC analytical results of hydrolysis sample. Temperature %Formic % Levulinic Time (min) (° C.) Acid Acid % HMF 300 90.2 2.4314.290 0.187

After filtration, 341.57 g of hydrolysate was recovered and extractedwith 677 g MIBK. The MIBK was added on top of the hydrolysate, allowedto mix for 30 minutes and settle for 30 minutes before separating theaqueous and organic layers. The residual MIBK in the aqueous layer wasremoved by vacuum distillation before the recycled raffinate was used inExample 120.

Example 120 Synthesis of LA+FA from Recycled Raffinate from Example 119

To a 3 neck flask equipped with magnetic stirring, a chilled condenser,and thermocouple was charged 295 g of the recycled raffinate fromExample 119. This raffinate contained 124 g H₂SO₄, 2.7 g levulinic acidand 1.3 g formic acid, as well as a small amount of un-reacted glucose.The raffinate was augmented with 21 g fresh water and 86 g of a 64%H₂SO₄ solution to bring the acid concentration of the aqueous mixture toapproximately 40%. The aqueous charge was then heated to 90° C. beforethe addition of 63.8 g of a sugar solution with the same composition asthe sugar solution in Example 115. The sugar solution was added viasyringe pump over 5 hours, at which point the reaction was cooled toroom temperature and filtered through a fine glass fritted glass filterto remove approximately 2 wt % insoluble humins. Again, analyses of thehydrolysis mixture at various times are presented in Table 14.

TABLE 14 HPLC analytical results of hydrolysis samples. Temperature %Formic % Levulinic Time (min) (° C.) Acid Acid % HMF 300 90.0 2.3255.764 0.138

Following cooling, the reaction mixture was re-heated to 90° C. and heldfor 60 minutes to more completely convert starting materials or stableintermediates to products.

TABLE 15 HPLC analytical results of hydrolysis samples during 90° C.post cook. Temperature % % Levulinic Time (min) (° C.) Formic Acid Acid% HMF Initial 25 3.218 5.914 0.041  0 90 3.252 6.105 0.041 60 90 3.1396.275 Non-Detectable

Example 121 For Large Scale Production

FIG. 4 provides a process flow diagram for an embodiment of Sugar toLevulinic Acid conversion/scale up. The following provides anexplanation of the scale up procedure.

The reaction was performed in a 2000 gallon glass lined reactor (R1) andthe solids that were formed were to be removed in the Hastelloycentrifuge (CFG) using the 8000 gallon poly tank for temporary storageof the hydrolysate. The centrifuged hydrolysate was then sent to 600gallon settling tank (EC-1) for extraction with methyl isobutyl ketone(MIBK). The organic extract (OEX) was sent to another 2000 gallon glassline reactor (R2) for concentration (distillation of excess MIBK) andthe hydrolysate was sent back to the 2000 gallon reaction vessel (R1)for the next reaction. (See FIG. 4.)

To a 2000 gallon glass line reactor (R1) equipped with condenser andthermocouple was charged 5540 lb water and 5380 lb of 93.3% (wt)sulfuric acid. The reactor was vented to a portable caustic scrubber(pH=12.0) pulling at 685 Torr. The reaction mixture was heated to 90° C.using pressurized steam. The CS90 (23% water, 69.3% fructose, 6.2%glucose, 1.5% other sugars) was added at 310 lbs/hour using a diaphragmpump. After all the CS90 had been added, the reaction mixture wasmaintained a 90° C. for an additional 90 minutes The reactor was cooledto 40° C. before subjecting the hydrolysate to centrifugation.

The reaction mixture was cooled to 44° C. in 255 minutes at which pointit was fed to the Hastelloy centrifuge (CFG). The hydrolysate was fed tothe centrifuge at 1600 lbs/hr and the centrifuge was spinning at 800rpm. The liquid flowing through the centrifuge basket was fed to an 8000gallon poly tank. Analysis of the first 2000 lbs of sample in poly tankshowed 1.25% solids, which was not a significant reduction in solids.Celite (filter aid) slurried in water was fed to the centrifuge to coatthe filter cloth followed by addition of hydrolysate from 2000 gallonreaction vessel (R1). ˜8000 lbs of hydrosylate was centrifuged and fedto the poly tank. The % solids in the poly tank was around 0.8% and the4000 lbs of hydrolysate in reaction vessel (R1) had 1.4% solids. Thehydrolysate from the poly tank was transferred to reaction vessel (R1)and the composite had 1.1% solids. The hydrolysate was then filteredusing a sock filter (100 micron) housed in a stainless steel canister.The filtered sample showed 0.74% solids. Filtration was continued usingthe same filter sock till the back pressure changed from 10-15 psig toaround 40 psig. The filter sock were changed in the following sequence:

100 micron—2 different socks

25 micron—1 sock

10 micron—1 sock

1 micron—2 socks

The final percent solids after multiple sock filtrations were 0.8%. 50lbs of Celite was added to the hydrolysate that was transferred back toGL5 and the hydrolysate was subjected to centrifugation. The centrifugedhydrolysate had 0.4% solids.

The 6000 gallon settling tank (EC-1) was first filled with 23000 lbs ofMIBK followed by addition of hydrolysate from poly tank, the agitatorwas running at 117 rpm during the addition of hydrolysate. Agitator wasturned off after 30 minutes and the top layer was sampled twice foranalysis.

TABLE 16 Analysis of Organic extract from settling tank (EC-1) Timeafter agitator was off % Levulinic % (minutes) Acid Formic Acid %Sulfuric acid % Water 15 0.94 0.45 0.5 1.19 30 0.95 0.45 0.68 1.28

The bottom layer (raffinate) was carefully transferred back to thereaction vessel (R1) using a diaphragm pump connected to a sock filtercanister with a 100 micron filter sock. 10580 lbs of raffinate wastransferred to the reaction vessel (R1).

12000 lbs organic extract (OEX) was transferred to another 2000 gallonglass line reactor (R2) for concentration of the final product. The MIBKin the OEX was distilled at 100 Torr maintaining the vent temperaturebelow 70° C. More material was transferred once the level in reactor(R2) was concentrated to 2000 lbs. After 28.5 hrs 4500 lbs of finalproduct was isolated with the following composition:

MIBK=92.3%, Levulinic acid=4.69%, Water=0.03%

The raffinate was also subjected to distillation to remove any MIBK. Thedistillation was performed at 100 Torr so as to maintain the venttemperature below 70° C. After 3730 lbs of water/MIBK mixture wasdistilled the raffinate was sampled for analysis.

Water=62.18%, Sulfuric acid=34.83%, Levulinic acid=1.58%, MIBK=0.58%Solids=0.15%

Example 122 1^(st) Recycle Raffinate Batch with CS90

To the 2000 gallon reaction vessel (R1) containing 8800 lbs of raffinate(1st recycle) was charged 451 lb water and 1690 lb of 93.3% (wt)sulfuric acid. The reactor was vented to a portable caustic scrubber(pH=12.0) pulling at 685 Torr. The reaction mixture was heated to 90° C.using pressurized steam. The CS90 (23% water, 69.3% fructose, 6.2%glucose, 1.5% other sugars) was added at 310 lbs/hour using a diaphragmpump. After all the CS90 had been added, the reaction mixture wasmaintained a 90° C. for an additional 90 minutes. The reactor was cooledto 40° C. before subjecting the hydrolysate to centrifugation.

The reaction mixture was cooled to 45° C. in 165 minutes at which pointit was fed to the Hastelloy centrifuge. The hydrolysate was fed to thecentrifuge at 2000 lbs/hr and the centrifuge was spinning at 800 rpm.The liquid flowing through the centrifuge basket was fed to a 8000gallon poly tank. Analysis of the sample in poly tank showed 0.8%solids.

6000 gallon settling tank (EC-1) was first filled with 23000 lbs ofrecycle MIBK followed by addition of 12500 lbs hydrolysate from polytank, the agitator was running at 117 rpm during the addition ofhydrolysate. Agitator was turned off after 30 minutes and the top layerwas sampled four times for analysis.

TABLE 17 Analysis of Organic extract from EC-1 Time after agitator wasoff % Levulinic % Formic % Sulfuric (minutes) Acid Acid acid % Water 151.36 0.74 0.13 1.1 50 1.35 0.74 0.15 1.08 65 1.37 0.74 0.15 1.06 80 1.450.75 0.16 1.07

The bottom layer (raffinate) was carefully transferred back to thereaction vessel (R1) using a diaphragm pump. 15000 lbs of raffinate wastransferred to the reactor (R1). Analysis of reactor contents (R1)showed high level of MIBK, so the raffinate was sent back to DC-1 forsettling. 60 minutes later 12560 lbs raffinate was transferred to the2000 gallon reaction vessel (R1) for distillation of MIBK.

12000 lbs organic extract (OEX) was transferred to another 2000 gallonglass lined reactor (R2) for concentration of the final product. TheMIBK in the OEX was distilled at 100 Torr maintaining the venttemperature below 70° C. More material was transferred once the level inreactor (R2) was concentrated to 2000 lbs. During couple of thetransfers raffinate layer was observed in the OEX that was drained in toa 250 gallon poly tote. (Total of 1000 lbs of raffinate drained in tothe tote) After 24 hrs 2000 lbs of crude product was isolated with thefollowing composition:

MIBK=86.55%, Levulinic acid=9.17%, Sulfuric acid=6.47%, Formicacid=1.46%, Solids=0.13%

The raffinate was also subjected to distillation to remove any MIBK. Thedistillation was performed at 100 Torr so as to maintain the venttemperature below 70° C. After 6645 lbs of water/MIBK mixture wasdistilled the raffinate was sampled for analysis.

Water=54.88%, Sulfuric acid=42.96%, Levulinic acid=3.55%, MIBK=0.06%Solids=0.14%

Example 123 2^(nd) Recycle Raffinate Batch with CS90

To the 2000 gallon reaction vessel (R1) containing 6000 lbs of raffinate(2^(nd) recycle) was charged 2090 lb water and 2430 lb of 93.3% (wt)sulfuric acid. The reactor was vented to a portable caustic scrubber(pH=12.0) pulling at 685 Torr. The reaction mixture was heated to 90° C.using pressurized steam. The CS90 (23% water, 69.3% fructose, 6.2%glucose, 1.5% other sugars) was added at 310 lbs/hour using a diaphragmpump. After all the CS90 had been added, the reaction mixture wasmaintained a 90° C. for an additional 90 minutes The reactor was cooledto 40° C. before subjecting the hydrolysate to centrifugation.

The hydrolysate was fed to the centrifuge at 2000 lbs/hr and thecentrifuge was spinning at 800 rpm. The liquid flowing through thecentrifuge basket was fed to an 8000 gallon poly tank. Analysis of thesample in poly tank showed 1.01% solids.

The 6000 gallon settling tank (EC-1) was first filled with 21905 lbs ofrecycle MIBK followed by addition of 10700 lbs hydrolysate from polytank, the agitator was running at 117 rpm during the addition ofhydrolysate. Agitator was turned off after 30 minutes and the top layerwas sampled four times for analysis.

TABLE 18 Analysis of Organic extract from EC-1 Time after agitator wasoff % Levulinic % Formic % Sulfuric (minutes) Acid Acid acid % Water 301.35 0.94 1.77 1.47 60 1.4 0.99 1.78 Not determined 90 1.42 1.0 Not Notdetermined determined 120 1.41 0.96 Not Not determined determined

The bottom layer (raffinate) was carefully transferred back to thereaction vessel (R1) using a diaphragm pump. 15750 lbs of raffinate wastransferred to the reactor (R1).

12000 lbs organic extract (OEX) was transferred to another 2000 gallonglass line reactor (R2) for concentration of the final product. The MIBKin the OEX was distilled at 100 Torr maintaining the vent temperaturebelow 70° C. More material was transferred once the level in reactor wasconcentrated to 2000 lbs. During transfers raffinate layer was observedin the OEX that was drained in to a 250 gallon poly tote. (Total of 4000lbs of raffinate drained in to the tote) After 30 hrs 2100 lbs of crudeproduct was isolated with the following composition:

MIBK=83.1%, Levulinic acid=7.04%, Formic acid=2.12%

The raffinate was also subjected to distillation to remove any MIBK. Thedistillation was performed at 100 Torr so as to maintain the venttemperature below 70° C.

Example 124

Into a 500 mL four neck round bottom flask was charged 102.57 gdeionized water and 103.04 g of 98% sulfuric acid. The round bottomflask was placed in a heating mantle and equipped with a magnetic stirbar, thermocouple, condenser, glass stopper and a rubber stopper thatheld the outlet tube of the syringe pump. In a beaker 38.03 g fructoseand 25.60 g deionized water were charged. The solution was mixed untilthe fructose dissolved, and it was transferred into a plastic syringesituated on a syringe pump. The acid and water mixture in the 500 mLround-bottom flask was heated to 90° C. and then, the fructose and watermixture was added via the syringe pump. The fructose was added over aperiod of 1.25 hours so the rate on the syringe pump was set to 37.6mL/hr. After a reaction time of 1.25 hours, all of the fructose had beenadded into the flask. The reaction was left to react for an additionalhour in order to react all of the fructose. The reaction was then shutdown and allowed to cool down. Samples were taken throughout the entirereaction and analyzed by HPLC. Once the reaction mixture was cool it wasfiltered through a fitted funnel and the solids were washed withdeionized water and acetone. The solids that were in the funnel wereplaced in a jar and put into a vacuum oven to dry. The final yieldnumbers and composition data are listed below.

Reaction Reaction Mol/L Mol/L Mol/L Mol/L Time(min) Temp ° C. FA LA HMFFructose 135 90.0 0.95 0.81 0.00 0.00

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Char 5.63 LA to Char Ratio 3.5 LA Molar % Yield on reactedsugar and HMF 81.4 FA Molar % Yield on reacted sugar and HMF 95.0

Into a 500 mL four neck round bottom flask was charged 102.09 gdeionized water and 103.04 g of 98% sulfuric acid. The round bottomflask was placed on a heating mantle and equipped with a magnetic stirbar, thermocouple, condenser, glass stopper and a rubber stopper thatheld the outlet tube of the syringe pump. In a beaker was charged 37.89g fructose and 26.07 g of deionized water. The solution was mixed untilthe fructose dissolved, and it was transferred into a plastic syringesituated on a syringe pump. The sulfuric acid and water mixture washeated to 90° C. and then the fructose and water mixture was added viathe syringe pump. The fructose was to be added over a period of 1.25hours so the rate on the syringe pump was set to 38.4 mL/hr. After areaction time of 1.25 hours, all of the fructose had been added into theflask. The reaction was left to react for an additional hour in order toreact all of the fructose. The reaction was then shut down and allowedto cool down. Samples were taken throughout the entire reaction andanalyzed by HPLC. Once the reaction mixture was cool it was filteredthrough a fritted funnel and the solids were washed with deionized waterand acetone. The solids that were in the funnel were placed in a jar andput into a vacuum oven to dry. The final yield numbers and compositiondata are listed below.

Reaction Reaction Mol/L Mol/L Mol/L Mol/L Time(min) Temp ° C. FA LA HMFFructose 135 90.2 0.94 0.82 0.04 0.00

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Char 5.9 LA to Char Ratio 3.3 LA Molar % Yield on reacted sugarand HMF 85.5 FA Molar % Yield on reacted sugar and HMF 97.5

Into a 500 mL four neck round bottom flask was charged 103.09 gdeionized water and 103.03 g of 98% sulfuric acid. The round bottomflask was placed on a heating mantle and equipped with a magnetic stirbar, thermocouple, condenser, glass stopper and a rubber stopper thatheld the outlet tube of the syringe pump. In a separate beaker wascharged 37.89 g fructose and 25.06 g deionized water. The solution wasmixed until the fructose dissolved, and it was transferred into aplastic syringe situated on a syringe pump. The sulfuric acid and watermixture in the round bottom flask was heated to 90° C. and then thefructose and water mixture was added via the syringe pump. The fructosewas added over a period of 2.5 hours so the rate on the syringe pump wasset to 18.8 mL/hr. After a reaction time of 2.5 hours, all of thefructose had been added into the flask. The reaction was left to reactfor an additional hour in order to react all of the fructose. Thereaction was then shut down and allowed to cool down. Samples were takenthroughout the entire reaction and analyzed by HPLC. Once the reactionmixture was cool it was filtered through a fritted funnel and the solidswere washed with deionized water and acetone. The solids that were inthe funnel were placed in a jar and put into a vacuum oven to dry. Thefinal yield numbers and composition data are listed below.

Reaction Reaction Mol/L Mol/L Mol/L Mol/L Time(min) Temp ° C. FA LA HMFFructose 210 90.3 1.00 0.89 0.04 0.00

Once the solids were dried, they were removed from the vacuum oven andweighed.

Grams of Char 5.6 LA to Char Ratio 3.8 LA Molar % Yield on reacted sugarand HMF 92.9 FA Molar % Yield on reacted sugar and HMF Near 100

Formic Acid Neutralization in MIBK Example 125

A 5 wt % solution of formic acid (0.3 g) in methyl isobutyl ketone, MIBK(5.2 g) was made. An equal molar solution of sodium hydroxide (0.2 g) inwater (1.9 g) was prepared. The two mixtures were combined in a vial andmixed well. Two layers formed in the vial and they were both tested byHPLC for % formic acid. The HPLC results show the MIBK solution droppedfrom 4.8% to 0.2% formic acid.

Example 126-127

Additional experiments were completed under the same procedure asexample 125. Changes in the initial scale of the experiment along with atest using less water were also performed. The results are summarized inTable 19.

Example 128

A 5 wt % solution of formic acid (0.3 g) in MIBK (5.1 g) was made.Sodium hydroxide powder (0.4 g) was added to the solution which is equalto twice the moles of formic acid. The mixture was mixed well for 1hour. After mixing, the MIBK was tested by HPLC for % formic acid. TheHPLC results show the MIBK solution dropped from 4.7% to 0% formic acid.

Examples 129-130

Further experiments were carried out under the same procedure as example128 along with changes in the base used. The results are summarized inTable 19.

TABLE 11 Initial % FA in % FA in g FA g FA Total g FA MIBK Water NaOHCaCO₃ CaH₂O₂ % FA in MIBK Water in in FA in EX. (g) (g) (g) (g) (g) (g)MIBK (HPLC) (HPLC) MIBK Water solution 125 0.27 5.20 1.88 0.23 4.85 0.226.51 0.011 0.123 0.134 128 0.25 5.08 NA 0.43 4.70 0.00 NA 0.000 NA 0.000129 0.27 5.01 NA 0.60 5.14 4.84 NA 0.243 NA 0.243 130 0.27 5.08 NA 0.464.98 2.34 NA 0.119 NA 0.119 126 0.27 5.03 0.25 0.25 5.03 0.00 NA 0.000ND 0.000 127 6.38 125.07 5.54 5.54 4.85 0.00 17.95 0.000 0.994 0.994

Table 19 shows that sodium hydroxide worked best at removing the formicacid from the MIBK compared to calcium carbonate and calcium hydroxide.Calcium carbonate does not show much promise in reducing the formic acidin MIBK. However calcium hydroxide does reduce the formic acid withequal molar ratios and may remove more if the ratio is increased.

Example 131 Isoamyl Alcohol

Aqueous sulfuric acid stock solutions were prepared at variousconcentrations and mixed with isoamyl alcohol to yield the compositions(in weight %) below. Phase behavior (1 phase vs. phase separated) wasdetermined visually. The data show that the solubility of the isoamylorganic solvent increases slightly as the amount of sulfuric acid in themixture increases (#2 vs. #16). At the appropriate composition ratio,the solubility of sulfuric acid in isoamyl alcohol can be high (#15).

% sulfuric Visual acid % organic % water Observations 1 49.0% 2.0% 49.0%1 phase 2 48.5% 2.9% 48.5% 1 phase 3 48.2% 3.6% 48.2% 2 phases 4 50.0%0.0% 50.0% 1 phase 5 15.0% 69.9% 15.0% 1 phase 6 15.4% 69.2% 15.4% 2phases 7 20.0% 0.0% 80.0% 1 phase 8 19.6% 2.0% 78.4% 2 phases 9 1.6%92.1% 6.3% 1 phase 10 1.8% 90.8% 7.4% 2 phases 11 10.0% 0.0% 90.0% 1phase 12 9.8% 2.1% 88.1% 2 phases 13 0.7% 92.8% 6.5% 1 phase 14 0.9%91.3% 7.9% 2 phases 15 0.0% 0.0% 100.0% 1 phase 16 0.0% 2.2% 97.8% 2phases 17 0.0% 92.1% 7.9% 1 phase 18 0.0% 90.7% 9.3% 2 phases

Example 132 m-Cresol

Aqueous sulfuric acid stock solutions were prepared at variousconcentrations and mixed with m-cresol to yield the compositions (inweight %) below. Phase behavior (1 phase vs. phase separated) wasdetermined visually. The data show that the solubility of the m-cresolorganic solvent in the in sulfuric aqueous phase is low (#2, #6), evenat high sulfuric acid concentration (#13). The compatibility of sulfuricacid with the m-cresol organic solvent is low (#8, #12, #15)

% sulfuric Visual acid % organic % water Observations 1 0.0% 1.3% 98.7%1 phase 2 0.0% 1.9% 98.1% 2 phases 3 0.0% 87.7% 12.3% 1 phase 4 0.0%86.0% 14.0% 2 phases 5 9.9% 0.8% 89.3% 1 phase 6 9.9% 1.4% 88.8% 2phases 7 0.2% 98.2% 1.6% 1 phase 8 0.3% 97.5% 2.3% 2 phases 9 19.9% 0.6%79.5% 1 phase 10 19.8% 0.8% 79.4% 2 phases 11 0.2% 99.2% 0.6% 1 phase 120.3% 98.5% 1.2% 2 phases 13 49.8% 0.5% 49.8% 2 phases 14 0.5% 99.1% 0.5%1 phase 15 0.9% 98.3% 0.9% 2 phases

Example 133 2-Ethyl Hexanol

Aqueous sulfuric acid stock solutions were prepared at variousconcentrations and mixed with to yield the compositions (in weight %)below. Phase behavior (1 phase vs. phase separated) was determinedvisually. The data show that the solubility of the 2-ethyl hexanolorganic solvent in the in sulfuric aqueous 2-ethyl hexanol phase is low(#1), even at high sulfuric acid concentration (#6). The compatibilityof sulfuric acid with the 2-ethyl hexanol organic solvent is low whenthe organic solvent content is very high (#10, #12, #14). When both theorganic solvent content and the sulfuric acid content are high, there isa region of compatibility (#15).

Visual % SA % organic % water Observations 1 0.0% 0.4% 99.6% 2-phase 210.0% 0.4% 89.6% 2-phase 3 19.9% 0.4% 79.7% 2-phase 4 49.8% 0.3% 49.8%2-phase 5 79.4% 0.8% 19.8% 1 phase 6 78.4% 2.0% 19.6% 2-phase 7 0.0%99.2% 0.8% 1 phase 8 0.0% 97.3% 2.7% 2-phase 9 0.1% 99.2% 0.7% 1 phase10 0.2% 98.1% 1.7% 2-phase 11 0.2% 98.8% 0.9% 1 phase 12 0.4% 97.8% 1.8%2-phase 13 1.9% 96.2% 1.9% 1 phase 14 2.3% 95.5% 2.3% 2-phase 15 34.3%57.1% 8.6% 1 phase 16 35.6% 55.6% 8.9% 2-phase

Examples 134-136 Backwash with Water to Remove Sulfuric Acid from MixedCresols

To a vial were added 5 g of CSTR hydrolysate material that had beenfiltered through 1 um glass fiber filter disc, spiked with LA (1.9%formic acid, 8 wt % levulinic acid, 50 wt. % sulfuric acid, and 40.1 wt.% water) and 5 g of mixed cresols from Aldrich. The vial was capped andthe mixture was shaken mechanically for 0.5 minutes. The layers wereseparated by centrifugation for 5 minutes and each layer was isolatedfor weight determination. The sulfuric acid in the organic layer wasdetermined by potentiometric auto-titration with potassiumhydroxide/methanol as titrant.

The organic layer from the hydrolysate partition experiment was thenwashed with the amount of DI water given in the table below. The layerswere then separated by centrifugation for 5 minutes and each layer wasisolated for weight determination. The sulfuric acid in the organiclayer was determined by potentiometric auto-titration with potassiumhydroxide/methanol as titrant. These experiments show a water wash canreduce the amount of sulfuric acid in the organic extraction phase.

Wt. % sulfuric Wt % sulfuric acid in organic Mass of DI water acid inorganic after initial wash (% by weight layer after partition relativeto the mass backwash with Example experiment of organic phase) DI water134 0.64 10 0.08 135 0.73 50 0.01 136 0.70 100 0.01

Aldrich MSDS indicates an 80% mixture of cresol isomers and 20% phenol.

GC/MS indicates the mixture to be 80% cresol isomers and 20%2,4-dimethylphenol.

Example 137 Neutralization to Remove Sulfuric Acid from Mixed Cresols

To a vial were added 5 g of CSTR hydrolysate material that had beenfiltered through 1 um glass fiber filter disc, spiked with LA (1.9%formic acid, 8 wt % levulinic acid, 50 wt. % sulfuric acid, and 40.1 wt.% water) and 5 g of a m-cresol/p-cresol blend (60/40 blend ratio byweight). The vial was capped and the mixture was shaken mechanically for0.5 minutes. The layers were separated by centrifugation for 5 minutesand each layer was isolated for weight determination. The sulfuric acidin the organic layer was determined by potentiometric auto-titrationwith potassium hydroxide/methanol as titrant to be 0.7% by weight.

The organic layer from the hydrolysate partition experiment was thenwashed with a saturated aqueous solution of 20% (by weight) of sodiumbicarbonate. The layers were separated by centrifugation for 5 minutesand each layer was isolated for weight determination. The sulfuric acidin the organic layer was determined by potentiometric auto-titrationwith potassium hydroxide/methanol as titrant to be non-detectable.

Acros Organics 99% m-cresol and Alfa Aesar 99% p-cresol were used in theabove example.

Examples 138 and 139 Backwash with Water to Remove Sulfuric Acid fromIsoamyl Alcohol

To a vial were added 5 g of CSTR hydrolysate material that had beenfiltered through 1 um glass fiber filter disc, spiked with LA (1.9%formic acid, 8 wt % levulinic acid, 50 wt. % sulfuric acid, and 40.1 wt.% water) and 5 g of isoamyl alcohol from Aldrich. The vial was cappedand the mixture was shaken mechanically for 0.5 minutes. The layers wereseparated by centrifugation for 5 minutes and each layer was isolatedfor weight determination. The sulfuric acid in the organic layer wasdetermined by potentiometric auto-titration with potassiumhydroxide/methanol as titrant.

The organic layer from the hydrolysate partition experiment was thenwashed with the amount of DI water given in the table below. The layerswere then separated by centrifugation for 5 minutes and each layer wasisolated for weight determination. The sulfuric acid in the organiclayer was determined by potentiometric auto-titration with potassiumhydroxide/methanol as titrant. The resulting organic layer was thenwashed again with 100 weight % water, further lowering the sulfuric acidcontent. These experiments show a water wash can reduce the amount ofsulfuric acid in the organic extraction phase.

Wt. % sulfuric Wt % sulfuric acid in organic Mass of DI water acid inorganic after initial wash (% by weight layer after partition relativeto the mass backwash with Example experiment of organic phase) DI water138 19.0 50 3.72 139 3.72 100 0.94

Example 140 Distillation of Formic Acid from a Mixture of Formic Acid,Levulinic Acid, Sulfuric Acid, Water, and Unknown Impurities

To a 3 neck round bottom flask equipped with a magnetic stir bar wascharged 255.60 g of a solution containing 11.12 g levulinic acid, 5.44 gformic acid, 99.43 g sulfuric acid, 139.61 g H₂O, and trace amounts ofseveral unknown impurities The flask was equipped with a thermocoupleand a short path distillation apparatus with a condenser chilled to 1 Cwith recirculating coolant. The distillation system was evacuated downto 40 Torr and before the kettle was heated to 45° C. The distillate wasexhibited a head temperature between 31-33° C. Distillate was allowed tocome overhead until the head temperature dropped below 28° C., at whichpoint the distillation kettle was cooled to 25° C., the pressureincreased to atmospheric pressure, and samples were taken from thekettle as well as distillation recovery flask. After sampling, thekettle was re-evacuated to 40 Torr and heated this time to 55° C. Theprocedure of distilling till the head temp falls, sampling, andredistilling at an elevated temperature was repeated until no moreformic acid could be observed in the distillation kettle.

TABLE 20 Analysis of distillate and kettle samples taken during thedistillation described in Example 140. % FA % LA Kettle Mass % % % g g gof of Cut Temp Sample (g) LA FA H₂SO₄ LA FA H₂SO₄ Charge Charge 1 65° C.Distillate 87.42 — 4.46 — — 3.90 — 77.87 0.00 Kettle 168.18 6.00 0.4855.0 10.09 0.81 92.50 16.16 89.73 2 75° C. Distillate 96.40 0.10 4.58 —0.10 4.41 — 88.16 0.87 Kettle 159.20 6.49 0.28 59.3 10.33 0.45 91.738.97 91.86 3 80° C. Distillate 100.46 0.10 4.55 — 0.103 4.57 — 91.190.91 Kettle 155.14 6.68 0.23 59.7 10.36 0.36 89.83 7.19 92.16 4 85° C.Distillate 102.72 0.10 4.50 — 0.10 4.62 — 92.21 0.92 Kettle 152.88 6.590.25 60.6 10.07 0.39 89.78 7.69 89.60 5 90° C. Distillate 108.84 0.114.45 — 0.12 4.85 — 96.82 1.04 Kettle 146.76 6.96 0.00 63.5 9.87 0.0090.04 0.00 87.77

Example 141 Vacuum Distillation of Formic Acid from a Mixture of FormicAcid, Levulinic Acid, Sulfuric Acid, Water, and Unknown Impurities withContinuous Addition of H₂O

To a 500 mL 4 neck round bottom flask equipped with a magnetic stir barwas charged 249.27 g of a solution containing 10.87 g levulinic acid,5.31 g formic acid, 97.13 g sulfuric acid, 136.38 g H₂O, and traceamounts of several unknown impurities. The flask was equipped with athermocouple, an addition funnel charged with 124.28 g DI H₂O, and ashort path distillation apparatus with a condenser cooled to 1 C withrecirculating coolant. The pressure of the system was reduced to 40 Torrbefore a heating mantle set to 45° C. was activated. When the solutionin the flask reached approximately 42° C., distillate was observed. Thehead temperature fluctuated around 31-32° C. during distillation. Whenthe distillate began to drip into the collection flask, H₂O from theaddition funnel was added dropwise at roughly the same rate as thedistillate was being removed. When all the H₂O from the addition funnelhad been added, the pressure of the system was raised to atmosphericpressure and the system was cooled. Samples of the reaction flaskmixture and distillate were taken, and the addition funnel was chargedwith more H₂O. The process of distilling with dropwise addition of H₂Owas continued until formic acid was no longer detected in thedistillation flask.

TABLE 21 Analyses of distillate and kettle samples throughoutdistillation described in Example 141. Mass H₂O % FA % LA Added Mass % %% g g g of of Cut (g) Sample (g) LA FA H₂SO₄ LA FA H₂SO₄ Charge Charge 1124.28 Distillate 93.88 0.06 2.53 — 0.06 2.38 — 44.72 0.51 Kettle 276.483.80 0.95 54.1 10.51 2.63 149.58 49.43 96.69 2 48.62 Distillate 45.760.03 1.15 — 0.01 0.53 — 54.62 0.11 Kettle 269.46 3.72 0.67 49.1 10.411.81 132.30 34.08 95.74 3 51.14 Distillate 46.63 0.02 0.79 — 0.01 0.37 —61.54 0.06 Kettle 263.48 3.66 0.52 31.3 10.37 1.38  82.47 25.93 95.34 447.25 Distillate 40.43 0.01 0.55 — 0.00 0.22 — 65.71 0.04 Kettle 279.623.74 0.44 42.9 11.48 1.22 119.96 22.89 105.57 5 47.86 Distillate 50.020.01 0.46 — 0.00 0.23 — 70.00 0.04 Kettle 244.88 3.72 0.34 44.0 10.340.84 107.75 15.85 95.08 6 48.63 Distillate 32.22 0.01 0.40 — 0.00 0.13 —72.41 0.02 Kettle 246.85 3.47 0.25 45.9 10.13 0.61 112.40 11.43 93.19 7101.4 Distillate 103.28 0.00 0.27 — 0.00 0.28 — 77.66 0.04 Kettle 236.033.55 0.15 40.7 10.19 0.35  99.67 6.57 93.70 8 96.82 Distillate 88.510.01 0.16 — 0.01 0.14 — 80.24 0.05 Kettle 239.65 3.38 0.09 43.1 10.080.22 105.54 4.06 92.68 9 97.74 Distillate 98.88 0.00 0.09 — 0.00 0.09 —81.92 0.01 Kettle 229.68 3.51 0.00 44.8 10.23 0.00 109.71 0.00 94.10

Levulinic Acid Partition Coefficients Examples 142-174

To a vial were added 5 g of CSTR hydrolysate material that had beenfiltered through 1 um glass fiber filter disc, spiked with LA (1.9%formic acid, 8 wt % levulinic acid, 50 wt. % sulfuric acid, and 40.1 wt.% water) and 5 g of organic solvent. The vial was capped and the mixturewas shaken mechanically for 0.5 minutes. The layers were separated bycentrifugation for 5 minutes and each layer was isolated for weightdetermination. The sulfuric acid in the organic layer was determined bypotentiometric auto-titration with potassium hydroxide/methanol astitrant.

The partition coefficient of levulinic acid in this system wascalculated according to:

${{Partition}\mspace{14mu} {Coefficient}} = \frac{m_{{LA},s}\text{/}m_{s}}{m_{{LA},a}\text{/}m_{a}}$

where m_(LA,s) is the mass of levulinic acid in the organic solventphase, m_(s) is the total mass of the organic solvent phase, m_(LA,a) isthe mass of the levulinic acid in the aqueous phase, and m_(a) is thetotal mass of the aqueous phase. The aqueous phase is pipette out of themixture is weight. Ms is then calculated by difference. m_(LA,a) ismeasure by HPLC and m_(LA,s) is calculated by difference. The partitioncoefficient of formic acid was calculated in a similar fashion.

Formic Acid % Sulfuric LA Partition Partition acid in Organic SolventCoefficient Coefficient organic phase NOTES 142 Methyl isoamyl 0.38 0.630.447 ketone 143 Methyl isobutyl 0.67 0.82 NR ketone 144 Diisobutyl 0.10.15 NR ketone 145 Acetophenone 0.65 1.03 4.2 146 Cyclohexanone 2.263.05 3.01 Required an additional 2.44 g of water to induce layerseparation 147 Isophorone 1.91 1.95 16.9 148 Neopentyl 2.01 9.61 21.2Required an additional 0.45 g alcohol of water to induce layerseparation 149 Isoamyl alcohol 2.33 6.91 19 Required an additional 6 wt% water to induce layer separation 150 n-hexanol 0.93 7.23 19.9 151n-heptanol 0.78 8.00 22.9 152 2-ethyl hexanol 0.5 12.3 12.8 153n-octanol 0.59 3.79 NR 154 1-nonanol 0.59 4.62 NR 155 1-undecanol 0.557.94 16 156 Phenol 3.94 0.57 1.02 157 4-methoxyphenol 1.77 6.1 158Guaiacol 0.72 0.31 0.11 159 2-sec butyl 1.88 0.25 0.042 phenol 160 Nonylphenol 0.26 0.14 NR 161 Methylene 0.23 0.14 NR chloride 162 Methylisobutyl 1.04 2.73 20.7 carbinol 163 Anisole 0.19 3.20 NR 164 Ethyleneglycol 0.2 0.71 0.22 di-n-butyl ether 165 Castor oil 0.04 0.37 0.75 166m-cresol 1.14 4.27 0.51 167 p-cresol 1.06 3.86 0.9 168 o-cresol 0.9 3.980.28 169 Cresol mix from 2.17 0.40 0.64 Aldrich* 170 60/40 m- 2.38 0.450.7 cresol/p-cresol 171 75/25 m- 2.29 0.41 0.57 cresol/p-cresol 172Diethyl 0.26 0.62 0.04 carbonate 173 Methyl salicylate 0.08 0.13 Belowdetection limit 174 2,4- 1.97 0.39 0.22 dimethylphenol NR = Not reported*Aldrich MSDS indicates an 80% mixture of cresol isomers and 20% phenol.GC/MS indicates the mixture to be 80% cresol isomers and 20%2,4-dimethylphenol.

Example 175 Formic Acid Separation from MIAK by Distillation

To a 1 L round bottom flask equipped with variac-controlled electricheating mantle, thermocouple, magnetic stir bar, pressure sensor,1-inch×18-inch vacuum-jacketed glass column packed with wire gauzepacking, and magnetic bucket-type reflux control head was added 76.0 gof formic acid and 76.0 g MIAK. The still was controlled at 200 torr fora duration of 100 minutes and a reflux ratio of 6:1 reflux:collect.Bottom flask temperature ranged from 77.1° C. to 101.5° C. while theoverhead temperature ranged from 60.1° C. to 61.1° C. Three fractionswere collected: Fraction 1, 13.8 g, 89.187% formic acid by HPLC,Fraction 2, 18.2 g, 88.842% formic acid by HPLC, Fraction 3, 26.4 g,88.944% formic acid by HPLC, Residual bottoms, 76.7 g, 3.261% formicacid by HPLC.

Example 176 Formic Acid Separation from Mibk by Distillation

To a 1 L round bottom flask equipped with variac-controlled electricheating mantle, thermocouple, magnetic stir bar, pressure sensor,1-inch×18-inch vacuum-jacketed glass column packed with wire gauzepacking, and magnetic bucket-type reflux control head was added 63.47 gof formic acid and 641.55 g MIBK. The still was operated at 763 torr fora duration of 260 minutes and a reflux ratio of 6:1 reflux:collect.Bottom flask temperature ranged from 115.3° C. to 116.5° C. while theoverhead temperature ranged from 97.1° C. to 114.7° C. Several fractionswere collected:

Fraction Mass (g) % FA by HPLC 1 14.72 13.925 2 33.38 12.949 3 38.0612.267 4 74.97 11.097 5 44.87 10.152 6 103.8 8.889 7 68.06 7.64 8 15.476.755 Bottoms 300.77 5.267

Although the present invention has been described with reference topreferred embodiments, persons skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention. All references cited throughout thespecification, including those in the background, are incorporatedherein in their entirety. Those skilled in the art will recognize, or beable to ascertain, using no more than routine experimentation, manyequivalents to specific embodiments of the invention describedspecifically herein. Such equivalents are intended to be encompassed inthe scope of the following claims.

1. A process to prepare levulinic acid comprising the steps: a) heatingan aqueous solution of a mineral acid to about 60° C. to about 110° C.in a reactor; and b) adding high fructose corn syrup, a mixture of atleast two different sugars, sucrose, an aqueous mixture comprisingfructose, an aqueous mixture comprising fructose and glucose, an aqueousmixture comprising hydroxymethylfurfural, an aqueous solution offructose and hydroxymethylfurfural, an aqueous mixture of glucose, anaqueous mixture of maltose, an aqueous mixture of inulin, an aqueousmixture of polysaccharides, or mixtures thereof to the heated aqueousacid in the reactor over a period of time to form a reaction mixtureincluding levulinic acid. 2-3. (canceled)
 4. The process of claim 1,wherein the mineral acid percentage by weight is from about 20 to about80 percent of the reaction mixture.
 5. (canceled)
 6. The process ofclaim 1, wherein the high fructose corn syrup contains between about 1and about 99 weight percent of fructose and from about 99 to about 1weight percent glucose with the remainder water, wherein the sugarcontent is between about 1 and about 99% by weight.
 7. The process ofclaim 6, wherein the high fructose corn syrup is added over a period offrom about 0.1 to about 40 hours. 8-28. (canceled)
 29. The process ofclaim 1, further comprising the step of heating the mixture to atemperature of from about 25° C. to about 160° C. to reduce any residualglucose levels. 30-35. (canceled)
 36. The process of claim 1, furthercomprising filtering out solids from the mixture including levulinicacid to provide a first filtrate. 37-38. (canceled)
 39. The process ofclaim 1, further comprising combining the mixture comprising levulinicacid with an extraction solvent to create an extraction phase and araffinate phase. 40-41. (canceled)
 42. The process of claim 39, whereinthe extraction solvent is selected from the group consisting of methyliosamyl ketone, methyl isobutyl ketone, diisobutyl ketone, acetophenone,cyclohexanone, isophorone, neopentyl alcohol, isoamyl alcohol,n-hexanol, n-heptanol, 2-ethyl hexanol, n-octanol, 1-nonanol,1-undecanol, phenol, 4-methoxyphenol, guaiacol, 2-sec butyl phenol,nonyl phenol, methylene chloride, methyl isobutyl carbinol, anisol,ethylene glycol di-n-butyl ether, castor oil, m-cresol, p-cresol,o-cresol, cresol mixtures, 60/40 m-cresol/p-cresol, 75/25m-cresol/p-cresol, diethyl carbonate, methyl salicylate, 2,4-dimethylphenol and mixtures thereof.
 43. The process of claim 42, furthercomprising recycling the raffinate phase to the reactor. 44-45.(canceled)
 46. The process of claim 45, further comprising adding highfructose corn syrup, a mixture of at least two different sugars,sucrose, an aqueous mixture comprising fructose, an aqueous mixturecomprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof to the raffinate phase in thereactor over a period of time to form a mixture including levulinicacid.
 47. The process of claim 46, further comprising separatinglevulinic acid, formic acid, or both from the extraction solvent. 48.(canceled)
 49. The process of claim 1, wherein the reactor is a batchreactor.
 50. (canceled)
 51. A process to prepare levulinic acidcomprising the steps: a) heating an aqueous solution of a mineral acidto about 60° C. to about 110° C.; b) adding a first aqueous mixturecomprising fructose and glucose to the heated aqueous mineral acid overa period of time to form a mixture including levulinic acid; c)optionally cooling the mixture to room temperature; and d) heating themixture, optionally in a sealed reactor, from about 25° C. to about 160°C. under pressure of 75 psi or below; e) optionally cooling the heatedmixture of step d) to room temperature; and f) filtering the mixture toprovide a first filtrate and solids. 52-54. (canceled)
 55. The processof claim 51, wherein the final filtrate is treated with a waterimmiscible solvent to form a water immiscible layer and a raffinate. 56.The process of claim 55, wherein the water immiscible layer is separatedfrom the aqueous layer and subjected to distillation. 57-66. (canceled)67. A process to prepare levulinic acid comprising the steps: a) heatingan aqueous solution of a mineral acid to about 60° C. to about 110° C.;b) adding high fructose corn syrup, a mixture of at least two differentsugars, sucrose, an aqueous mixture comprising fructose, an aqueousmixture comprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures thereof to the heated aqueous mineral acidover a period of time to form a reaction mixture in a reactor to form amixture including levulinic acid and solids; c) filtering the solidsfrom the mixture, optionally after cooling; d) adding a water immiscibleliquid to the mixture so that the mixture forms first and second layers,wherein greater than 90% of the mineral acid is in the first layer andgreater than 90% of the water immiscible liquid is in the second layer;e) recovering levulinic acid and optionally formic acid from the secondlayer; and f) recycling the first layer back to the reactor. 68-72.(canceled)
 73. The process of claim 67, wherein the mineral acidpercentage by weight is from about 20 to about 80 percent of thereaction mixture.
 74. (canceled)
 75. The process of claim 67, whereinthe mineral acid percentage by weight is from about 40 to about 80percent of the reaction mixture.
 76. (canceled)
 77. The process of claim67, wherein the water immiscible liquid is selected from the groupconsisting of methyl iosamyl ketone, methyl isobutyl ketone, diisobutylketone, acetophenone, cyclohexanone, isophorone, neopentyl alcohol,isoamyl alcohol, n-hexanol, n-heptanol, 2-ethyl hexanol, n-octanol,1-nonanol, 1-undecanol, phenol, 4-methoxyphenol, guaiacol, 2-sec butylphenol, nonyl phenol, methylene chloride, methyl isobutyl carbinol,anisol, ethylene glycol di-n-butyl ether, castor oil, m-cresol,p-cresol, o-cresol, cresol mixtures, 60/40 m-cresol/p-cresol, 75/25m-cresol/p-cresol, diethyl carbonate, methyl salicylate, 2,4-dimethylphenol and mixtures thereof.
 78. The process of claim 77, wherein thehigh fructose corn syrup, a mixture of at least two different sugars,sucrose, an aqueous mixture comprising fructose, an aqueous mixturecomprising fructose and glucose, an aqueous mixture comprisinghydroxymethylfurfural, an aqueous solution of fructose andhydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixtureof maltose, an aqueous mixture of inulin, an aqueous mixture ofpolysaccharides, or mixtures added over a period of from about 0.1 toabout 40 hours. 79-99. (canceled)